View Full Version : HD extractor springs & CRANE O-rings
Where are you guys buying your replacement heavy-duty extractor springs and CRANE O-rings? I'm down to one spare and need to order a few.
g and r tactical. $3, a bargain.
My springs are from SAW. I get the rings for free from a friend. I have a few I can send your way. Professor, send me a PM.
LukeMacGillie
07-18-06, 09:03
Last time I was at Crane the word was that they were going with the D-fender as it was cheaper to buy them, then to produce the O-ring to their specifications.
That was in 2004, might have changed since then.
Pat_Rogers
07-18-06, 09:27
The Reliability Enhancement Kit #2 uses the "O" Ring.
I get my springs from either SAW or gunsprings.com. The O rings I get from ADCO.
The Reliability Enhancement Kit #2 uses the "O" Ring.
Pat, my apologies if this has been covered on 10-8 but my memory isn't what it used to be:
Are the "O" rings that Crane uses different than the ones found in Home Depot for instance? Last November I bought a few at Home Depot and took then as spares to the Super Dave Harrington class just in case anyone had issues but I never used them. I have only used the ones I purchased from ADCO because I'm worried about using the Home Depot ones for any length of time.
Thanks.
Brownells and DPMS carry the wolff extra power springs.
Pat_Rogers
07-18-06, 11:08
Roger, different. The #60 "O" rings commonly available would work for a short time in a pinch (and i have used a whole bunch of them on my guns as well as others).
Having said that, we were able to purchase a great quantity of the Crane type at a significant savings.
I understand that some Defenders were used. Crane stated that they felt there was no discernable difference in operation and they went to the O rings.
The owner of Defender probably has another view on this, and i have used several Defenders along with "O" rings without issue.
Sully carries O-rings. These are the synthetic versions that are heat resistant up to 400 degrees or so, chemical resistant, no cheapie rubber ones.
www.defensive-edge.net
Thanks for the scoop Pat!
Sully's running a special on O-rings this month. These are the synthetic versions that are heat resistant up to 400 degrees or so, chemical resistant, no cheapie rubber ones. $1 a piece if you can swing that.
www.defensive-edge.net
Thanks jmart!
I see Sully has received some very favorable reviews in SWAT Magazine so I would have no issues ordering from them and the fact that they are selling them for a $1 a piece makes it a no-brainer :D
Pat_Rogers
07-18-06, 12:11
Sully is GTG.
Yes, we at MGI do have a different view about using the O-ring, but with the small amount of money I make on the D-Fender, I'm not going to make a big issue out of it.
Fought that battle too many times.
Suffice it to say that while the Crane O-ring can be gotten as an issue item that costs a unit nothing, we get orders in the magnitude of thousands of D-Fenders per year from Spec-Ops units buying them for their entire units with their discretionary funding.
They can get the issue Crane O-ring free, but they spend the money to buy alot of our D-Fenders and replace the Crane O-Rings with D-Fenders.
I guess that says something.
Many go to allied military Spec-Ops units as well.
Run what you like, it's your gun.
I just ordered three O-rings from Sully. Unfortunately he doesn't list the HD extractor springs and inserts as separate items, he only includes those with his nickeled extractor upgrade kit.
Does the O-ring work well enough with the std rifle spring/blue insert combo, or to get the benefit do you need to pair them with HD springs? My application would be for a BM 16" Patrolman's Carbine Upper, w/carbine length gas system. If I need the HD springs, where's a good place to get just a couple? If I'm not mistaken, SAW requires a minimum purchase order and I don't think just 3-4 springs would qualify.
I have a handful of the Crane Springs and O Rings on hand....actually ordered them from Grant in order to have them in stock for folks.
Thanks, I may be contacting you later this week.
In your experience, do you need to run the HD spring with an O-ring or is it just added insurance?
An alternative to the SAW spring is Wolff, which you can buy in small quantities from Brownells. You should have the BLACK insert in a carbine.
What barrel lengths require, or are equipped, with the HD/black insert combo? I thought that was the combo to use in anything with a carbine-length gas system, so 16", 14.5" SBRs should all use that combo. I also thought the regular spring/blue insert was std equipment for rifle length gas systems. Am I mistaken?
What barrel lengths require, or are equipped, with the HD/black insert combo? I thought that was the combo to use in anything with a carbine-length gas system, so 16", 14.5" SBRs should all use that combo. I also thought the regular spring/blue insert was std equipment for rifle length gas systems. Am I mistaken?
jmart: My BAD. BLACK insert for a carbine; blue for rifle. Edited for correction above.
Thanks, I may be contacting you later this week.
In your experience, do you need to run the HD spring with an O-ring or is it just added insurance?
In my experience no but it doesn't hurt. If you're running a HD spring and performing regular maintenance you probably don't need an O-ring. But it's extra insurance and that is never a bad thing :)
As Marc said, it doesn't hurt to run both. The "kits" I have are the Crane O ring and the Crane HD Spring.
Giff
As Marc said, it doesn't hurt to run both. The "kits" I have are the Crane O ring and the Crane HD Spring.
Giff
Giff - Tell me more about the Crane HD Spring. How does it compare to the Wolff or Colt HD Spring?
Giff - Tell me more about the Crane HD Spring. How does it compare to the Wolff or Colt HD Spring?
Good question. I'll look at it closer and let you know....or I'll ask Grant :D
For some odd reason I thought the black inserts were the ones you didnt want. So you guys are saying blue for rifle and black for carbine correct?
For some odd reason I thought the black inserts were the ones you didnt want. So you guys are saying blue for rifle and black for carbine correct?
IIRC Troy posted that the color of the insert did not matter and that the only thing it was used for was to denote the upgrade to the HD extractor spring was performed. This info might be wrong or outdated, I don't know but that's what he posted.
I've heard two stories:
(1) Insert color doesn't matter. The only reason there are two different colors was to make it easier for armorers/assembly personnel to differentiate between rifle strength springs and carbine HD springs.
(2) Insert color does matter. The black insert is made of a denser material and should be paired with the HD spring.
Sully subscribes to the latter since, if I remember correctly, he makes that point on his website with his extractor upgrade package. But at the same time, it seems almost counter-intuitive. Part of me thinks the std weight/strength spring would benefit more from additional support than the HD springs since it already runs a stronger spring wire to begin with. Who knows.
In the end, I'm not really concerned too much about the insert color/density, I'm just trying to figure out if I should switch over to the heavier spring along with the addition of the O-ring or does the O-ring by itself offer enough benefit. I guess like someone above said, just consider it added insurance.
So as long as I stick with an HD spring and either a Crane o ring or a Defender, then I'll be on top of things, right....?
I usualy stay up on this kind of stuff, but for some reason I have been lax on this..:(
So as long as I stick with an HD spring and either a Crane o ring or a Defender, then I'll be on top of things, right....?
I usualy stay up on this kind of stuff, but for some reason I have been lax on this..:(
Correct!
Jmart - I certainly doesn't hurt to run an O ring or Defender in addition to an HD spring. No offense to Troy, he's a wealth of information but in this case I would listen to Sully ;)
So as long as I stick with an HD spring and either a Crane o ring or a Defender, then I'll be on top of things, right....?
I usualy stay up on this kind of stuff, but for some reason I have been lax on this..:(
In the case of the D-Fender, it is engineered to provide 4x the normal extractor tension, and does not require any extra power spring. The D-Fender does virtually the entire job by itself anyway, and the spring becomes primarily a device for maintaining the locating position for the D-Fender.
I've been told by Mack, that the black D-Fenders are a bit stiffer than the original blue ones that we used to make, but I have no idea if this also carries over into the colored spring inserts, or if it is just a coincidence that the colors are similar.
I really can't speak to the O-ring situation, because there are so many different ones out there, that there's no way for me to accurately address that. All I can say about the O-rings is that the "O" shape is not ideal for this application(regardless of material used), and our testing showed marked improvements in reliability and longevity when the "D" shape with the wedge profile was introduced.
Several very high round-count tests were done on the D-Fender by Crane, and they never did get it to fail, and issued the DTC Safety Certification for military use. I have a copy of the DTC letter in my posession, and I've posted the text on "another gun website". The key parts of the letter's text were "extensively tested on 3 variations of M16/M4 weapons", "always improved reliability", and "without negative effects".
Yes, it costs alot more than an O-ring.
YMMV.
I've been running both my carbines with obly the Wolff XP extractor spring and they've been running 100%.
Lately I've been thinking of adding a D-Fender as well for some extra Murphy proofing but I was wondering if there can be a negative effect becuase of too much extractor tension.
Does anyone know if too much extractor tension could cause issues with feeding or something else?
Its a possibility, but I've never witnessed it. Almost everyone at courses I attend (except the totally new shooters) have a combo of a stronger spring with an O-ring/Defender.
Partners behind the line told me that they've noticed my brass lands much further out than when I ran an upgraded spring alone, but all I've noticed is that I've never had an FTE since. Before, I used to have at least 1 FTE about every 1300 rounds even with the upgraded spring and insert.
It's definitely necessary to have the blue/black rubber insert when using Wolff XP Srprings??? I have used only the spring and "o" rings (without the insert) for a few range sessions (about 400 rounds) with no FTF/FTE issues. I'm missing something not using the inserts?
Kisara,
Thanks for the feedback. I will probably go ahead and give it a try as it sounds like a worthwhile addition for extra insurance.
TacDoc,
IMHO, the little rubber extractor insert, regardless of it's stiffness, adds such an insignificant amount of tension that it doesn't really matter.
Thank you Yojimbo... just what I wanted to hear!
IMHO, the little rubber extractor insert, regardless of it's stiffness, adds such an insignificant amount of tension that it doesn't really matter.
I've always thought the purpose of the insert is to support the base of the spring and keep it from tipping. By supporting the base you make sure the spring compresses and rebounds in a straight line without tipping over. That and it could also serve as a bumper stop so the spring never gets to full compression.
Thors ~ Hammer
07-23-06, 17:36
I have a gray insert I have been using. Not sure where I got it but has been working, it does throw the brass forward instead of back. I inserted a D-Fender it seems to help but still not strong enough for my liking.
Does anyone know where the gray inserts came from? Where these used in early guns?
I've always thought the purpose of the insert is to support the base of the spring and keep it from tipping. By supporting the base you make sure the spring compresses and rebounds in a straight line without tipping over. That and it could also serve as a bumper stop so the spring never gets to full compression.
I've heard that too but over the years I've seen many people run the extractor spring without ever having extraction issues caused by "tipping".
I think once the extractor is installed on the bolt and extractor pin is pushed in there's really no where for the extractor spring to go.
This kind of reminds me about the 1911 debate about FLGR vs USGI spring guide and plug...;)
Again, besides "tipping" the other benny could be a bump stop. I would imagine that it would bad for the spring to completely compress and bottom out. The insert may serve as astop to prevent that happening, but I'm just guessing that that's a purpose it serves.
It would seem intuitive that without a case in the bolt/extractor, the spring would be at maximum lift and there would be space between the tip of the insert and the extractor. Insert a case, especially one with a large rim and/or shallow groove and now the spring compresses. How far can it compress, until it completely stacks up or until a bumper stops it from compressing any further? I'm thinking a situation similar to running a carbine buffer in a rifle A2 tube. Bad juju from what I hear.
Pat_Rogers
07-24-06, 07:07
Dean Caputo, a Colt Armorer Instructor, states that there is a different composition between the different color inserts, with black being "stronger".
I have seen USAF GAU/ GUU's with white inserts (old time M16A1 days) but the mil standard for M4's is black.
Some commercial makers use blue, as well as using the older extraxtor spring. We generally find this at class after the barrels get hot and the FTE begin.
Not that its right but I use Wolf springs and blue inserts. I know it isn't recommended but in thousands of rounds I have never had a failure attributed to extraction.
Pat_Rogers
07-24-06, 12:53
And some people drink milk with their Scotch.
Getting away with something isn't the same as doing it right. My opinion here is that yor Wolff spring is strong enough to do the job on it's own, even with the blue insert.
Your experience is that it works. However, would it work on the long haul? Would it work for 10 guns? 10,000 guns?
I prefer to do it right from the start. Of course you can do whatever you want, but i hate to see guys show up in class and have non functional equipment.
In all of my company guns we use a Wolff spring, black insert and "O" ring.
I'm constantly wondering why so many forum frugalists insist on running what MIGHT work versus the prescribed configuration for success. Perhaps their carbines are just for fun and not for their intended purpose (?). We're not talking about expensive items here. A proper spring and buffer (and an O/D/X-ring if you're running an SBR or feel better with one) can't cost much more than a Happy Meal if that much.
If Dean Caputo sez the black insert is different (higher durometer/stiffness?) and has a higher likelihood of making my carbine more reliable, I'm using the black insert.
Pat Rogers sees way more rounds fired through M4ish carbines in a year than most of us will see in a lifetime. This give him a perspective that few of us have the benefit of. If Pat sez that he sees recurring issues with a particular brand or configuration, I take note.
I'm constantly wondering why so many forum frugalists insist on running what MIGHT work versus the prescribed configuration for success. Perhaps their carbines are just for fun and not for their intended purpose (?). We're not talking about expensive items here. A proper spring and buffer (and an O/D/X-ring if you're running an SBR or feel better with one) can't cost much more than a Happy Meal if that much.
If Dean Caputo sez the black insert is different (higher durometer/stiffness?) and has a higher likelihood of making my carbine more reliable, I'm using the black insert.
Pat Rogers sees way more rounds fired through M4ish carbines in a year than most of us will see in a lifetime. This give him a perspective that few of us have the benefit of. If Pat sez that he sees recurring issues with a particular brand or configuration, I take note.
Aubrey,
Please don't take my questions as evidence of being "overly frugal". My situation is I've been trying to get by without doing the necessary things, so lately I've been trying to correct that. I posed the question whether or not a HD spring was needed given that I will soon be running an O-ring. I'm not opposed to buying them if recommended, but I'm just trying to figure out what the recommended config is. I've seen all sorts of recommendations -- regular spring w/Defender or O-ring, HD spring only, or HD + Defnder or O-ring. There certainly doesn't seem to be any standard config as far as I can tell, that's why I'm asking the questions.
Submariner
07-24-06, 13:38
As a result of attending Dean Caputo's class and learning about extractors and springs, I have gone through all 31 Colt bolts we have in the armory for 16" and 14.5" carbine uppers. I have found red, white and blue extractor spring inserts and rifle extractors on most, depending on the age of the bolt or whether we have actually been shooting it. I called Brownells this morning to order Colt Extractor Spring Assemblies (gold spring and black insert) (#160-304-025/SP64088@$3.52). It turns out that the price has gone up to $5.34 (after discount).
I ended up ordering Wollf spring 3-packs and 10-packs of black inserts, saving more than $30.00 over the cost of Colt parts. NOTE: The warning on the Wolff XP extractor spring package says to use only with factory insert. If there were not a good reason for that note, lawyers excepted, it would not be there.
ETA: O-rings were already on hand courtesy of the Brothers Karamazov. :D
Pat_Rogers
07-24-06, 14:05
The Crane Reliability Enhancement Kit contains enhanced extractor spring, black insert and "O" ring (as well as bolt rings).
That is their standard for the M4/ M4A1 Carbines under their cognizance.
All of these are available from Brownell's (and others).
jmart,
Please don't take it personal. I wasn't directing my comment at any one in particular. Some people who really know the truth are sharing it here, and it doesn't cost much to take advantage of it.
If anyone here is frugal, it's Submariner. I respect frugal. One has to be frugal to be able to afford 31 genuine Colt's bolts.
What I don't understand is being cheap, unless it doesn't matter (i.e., for fun versus for real).
Aubrey/Pat/Everyone else,
Thanks.
Who sells the black inserts alone?
Never mind, foud 'em at Brownell's. I was feeling guilty about running my Wolff springs and "o" rings alone...
Submariner
07-24-06, 14:50
Who sells the black inserts alone?
Brownells #078-000-071 Extractor Buffers 10-Pak, 10P71 $13.40
Small items first class shipping, $3.95.
Dave Berryhill
07-24-06, 14:57
The Crane Reliability Enhancement Kit contains enhanced extractor spring, black insert and "O" ring (as well as bolt rings).
That is their standard for the M4/ M4A1 Carbines under their cognizance.
All of these are available from Brownell's (and others).
Pat knows his stuff. If you compare a Colt black insert and a Colt blue insert you'll see that the black insert is harder to compress. It does add extra tension to the extractor spring, even a heavy duty one. Ned Christiansen did some pretty intersting testing and found that even with a Wolff heavy duty extractor spring, black insert and an O-ring that there wasn't too much extractor spring tension due to the fulcrum point of the extractor (the extractor pin). Obviously the military has come to the same conclusion.
I've been trying to get some of these parts in stock for a while. I should have heavy duty extractor springs, black inserts, O-rings similar to the ones in the Crane kit, McFarland 1-piece gas rings and standard gas rings in stock in a week or two.
Okay. I'm convinced that as far as extraction tension goes more is better!:D
Now, excluding cost, why would you choose an o-ring instead of the MGI Defender which is specifically designed to be used for this purpose and will more than likely last the life of the bolt?
Also, I've been using Wolff XP extracotrs spring for many years but are there other extra power springs that offer superior performance?
Pat_Rogers
07-26-06, 10:08
Yojimbo- I'm not sure of the genesis of either. My memory is that the "O" ring came first, and that the Defender was a follow on. TWL would be better able to tell you that as he is intimately involved, whil i am only a trigger puller.
I haven't had any issues with longevity of either item. Extraction is enhanced in any case with either, but again, TWL can give you numbers related to the test data (which in any case is out of my pay grade).
Yojimbo, I really can't say one way or another why the D-Fender would be better. The fact of the matter is that neither I nor anyone I know has destroyed a Crane O-ring. Note the emphasis on Crane O-ring. Included in that group is Steve, and Pat--two guys that have never been accused of maintaining (by the book), let alone babying an AR. Some on the errornet seem convinced that an o-ring is an o-ring, I am not one of them.
I can understand people being leery of rubber parts inside firearms, look at Shok-Buffs for crying out loud. But until I, or someone I trust can prove that the Crane O-ring is deficient in some manner, I remain sold on them. Again, that isn't to say that the D-Fender isn't everything the manufacturer claims-it very well may be.
As long as you are buying proven quality in a product, most any product, I believe that you are making a solid choice for the long run.
Pat and Damian,
Thank you for the feedback gentlemen!
Pat_Rogers
07-26-06, 13:51
Clean? What's that?
Submariner
07-26-06, 15:57
Pat,
Who drinks milk with scotch?
Not Pat, but didn't that fine congresscritter from Harlem, Adam Clayton Powell, drink Scotch with milk (for his ulcers). Pat probably knew him.:D
Pat_Rogers
07-26-06, 16:00
No Paul, i didn't know him, but did know others.
There are a lot of people who do strange things- and the gun world has it's fair share...
Submariner
07-26-06, 16:52
Well, Brownells came through with everything in two days. I had a dust cover spring break (yeah, Pat, we shut them at home, too) so I even ordered several and a spare snap ring just in case I lose/destroy the one on the gun. Swapping extractor springs and checking extractors beats watching TV.
That Pat Rogers guy doesn't know crap!
Yes I am kidding. Pat has forgotten more about gear/shooting and tactics than I will ever know. :D
I sell the CRANE O-Rings and CS Spring. I do not think the Wolf Springs are CS. This is a bad thing IMHO. SS springs take a set everytime you pull the trigger. CS springs take a set the first time they are used and never again. This is why I run CS extractor and buffer springs.
C4
The Crane Reliability Enhancement Kit contains enhanced extractor spring, black insert and "O" ring (as well as bolt rings).
That is their standard for the M4/ M4A1 Carbines under their cognizance.
All of these are available from Brownell's (and others).
Pat, IIRC, the rings are one piece, ie the McFarland's?
Sub, thanks for that part number, I needed that!
Pat_Rogers
07-27-06, 02:54
I have heard that there are some one piece rings in some kits.
However, i have only seen 3 piece rings in the kits.
That Pat Rogers guy doesn't know crap!
I sell the CRANE O-Rings and CS Spring. I do not think the Wolf Springs are CS. This is a bad thing IMHO. SS springs take a set everytime you pull the trigger. CS springs take a set the first time they are used and never again. This is why I run CS extractor and buffer springs.
C4
Grant,
Who's CS extractor springs are you selling? I wasn't aware that ISMI was making extractor springs.
Are you inferring that Wolff (that's two "f"s) are "Stainless Steel" (AKA Corrosion Resistant Steel or CRES in my biz)? I thought that Wolff springs were high-quality music-wire springs, but than I don't know much...
Grant,
Who's CS extractor springs are you selling? I wasn't aware that ISMI was making extractor springs.
Are you inferring that Wolff (that's two "f"s) are "Stainless Steel" (AKA Corrosion Resistant Steel or CRES in my biz)? I thought that Wolff springs were high-quality music-wire springs, but than I don't know much...
The springs I have are part of the Crane upgrade kit. I don't know who made them. SS springs wear down every time you pull the trigger. CS springs do not. This is why you want to remove them from your weapon.
C4
Submariner
07-27-06, 20:24
Once upon a time I was the Operational Test Director for Submarine Sonar Systems (scary, huh?). I went from the operational side (chasing Sovs) to seeing if IBM met performance specifications, including in the area of repairability. As a result, I became acquainted with something called Mean Time Between Failure (MTBF) for parts. While thinking about the CS vs SS spring issue, MTBF came to mind.
Grant- I suspect the same folks who provided you the Crane CS extractor springs probably have a handle, or know who does, on the MTBF (for any given "failure" the define) on the various parts, e.g. CS, SS, or"music wire" extractor springs, buffer springs or magazine springs or O-rings, D-fenders or chicken guts. Parts were generally put in the system based on some sort of balancing test or cost benefit analysis between an expensive part with a long MTBF vs. a more expensive part with a slightly longer MTBF. Perhaps they might be persuaded to share (you have not because you ask not.)
Like you, I am enthralled with the one-time set of CS springs and that "SS springs wear down every time you pull the trigger. CS springs do not". (Dean Caputo wasn't when I asked him.) But what does that mean in the real world? How many rounds before some bad thing happens with the CS spring (MTBF). In the same test, how does the Wolff spring do? The Colt spring? The SAW spring? These are objective tests. Then, is the higher cost worth the increased MTBF? This is a subjective test. I suspect the testing has been done; otherwise, how could a decision be taken to go to CS springs? If this gouge were available to mere taxpayers, it certainly would clear up much on this issue so we can rationally decide what to purchase.
and not all chrome-silicon springs are created equal...
Submariner
07-27-06, 20:56
and not all chrome-silicon springs are created equal...
Amen!
and not all chrome-silicon springs are created equal...
This is true. ISMI is the hands down leader when it comes to CS springs IMHO. They also make you pay for it.
To address bubble heads comments, I would still change out my extractor and buffer springs (even whenusing ISMI) about ever 5,000-6,000 rounds. You are simply doing PM's on your weapon and is just one less thing to worry about.
My view of the world is that springs are cheap, change frequently. :D
C4
Submariner
07-28-06, 04:53
Bubblehead also learned that Preventive Maintentenance periodicity is based on that MTBF. (Replace before it is likely to fail; what a concept!) So replacement every, say, 5,000 rounds is great so long as the MTBF is greater than 5,000 plus some fudge factor that makes you feel all warm and fuzzy (and at a cost that you are willing to pay.)
Three $18 buffer springs here and two dozen $10 magazine springs (for a $10 magazine) there and pretty soon we are talking a case of quality ammunition or a college education. As for extractor springs, this reminds me of the magic beans Jack traded for the family cow.:D Ooh, they are from Crane. Great! On what basis, i.e. objective standard(s), did Crane select them? Are they, too, Heat Treated, Shot Peened & Stress Relieved as are other premium CS springs? Warranty? Availability (can mere taxpayers buy them from vendors here?) and price? Oh, and until we know the MTBF of these versus the other choices, how do we really know what is "better" or how often to replace/buy them? YMMV.
Pat_Rogers
07-28-06, 08:39
For about the past year we have been playing with buffer/ extractor CS/moly plated springs from Tactical Springs. The parent company is well known in the competitive shooting world.
I don't have the knowledge, equipment or time to do proper testing- therefore i stick w/ pulling triggers.
I have absolutely nothing negative to say about them. They work.
Are they better/ longer lasting/ attract women with firm American yabbos? Can't say. Do they work at least or better then other springs i have used?
Yes, subjectively.
I run them in those guns that i use, and will let you know if i see any aberrations.
Re PM. I would prefer to change everything out at regulated intervals. Understand Paul what you are saying about cost. Crane is looking at the round counter computer in the PG for exactly those reasons- to ensure necessary parts are changed before failure, and to not change anything unnecessarily.
I keep a ruler on by workbench with buffer spring length (+ and -) for M4 and M16 marked.
On those rare occasions when i do a real deal cleaning i'll remove the spring and measure it, replacing if necessary (yes Paul, i carry the ruler in my kit bag as well...).
I have had Wolff extractor springs go for 7-10k rounds (with the "O" Ring) before problems- too wide a variation and not enough statistical sampling to make any decisions.
Just fyi...
Bubblehead also learned that Preventive Maintentenance periodicity is based on that MTBF. (Replace before it is likely to fail; what a concept!) So replacement every, say, 5,000 rounds is great so long as the MTBF is greater than 5,000 plus some fudge factor that makes you feel all warm and fuzzy (and at a cost that you are willing to pay.)
Three $18 buffer springs here and two dozen $10 magazine springs (for a $10 magazine) there and pretty soon we are talking a case of quality ammunition or a college education. As for extractor springs, this reminds me of the magic beans Jack traded for the family cow.:D Ooh, they are from Crane. Great! On what basis, i.e. objective standard(s), did Crane select them? Are they, too, Heat Treated, Shot Peened & Stress Relieved as are other premium CS springs? Warranty? Availability (can mere taxpayers buy them from vendors here?) and price? Oh, and until we know the MTBF of these versus the other choices, how do we really know what is "better" or how often to replace/buy them? YMMV.
I think springs will function (in most part) for much higher round count. By keeping fresh springs in your weapon, you are decreasing felt recoil and making sure that you have a reliable weapon.
ISMI buffer springs are pricey @ $18 apiece. I don't full believe that that their high end mag springs are needed though. I think any CS spring will work just fine as these springs are not put the torture that the other two are.
I have no entry and or exit criteria for the Crane Springs. As far as I can tell, they are the same price as the Wolff ones so we its not like the ISMI buffer spring VS teh $5 SS one.
C4
Submariner
07-28-06, 10:27
Re PM. I would prefer to change everything out at regulated intervals. Understand Paul what you are saying about cost. Crane is looking at the round counter computer in the PG for exactly those reasons- to ensure necessary parts are changed before failure, and to not change anything unnecessarily.
I keep a ruler on by workbench with buffer spring length (+ and -) for M4 and M16 marked.
On those rare occasions when i do a real deal cleaning i'll remove the spring and measure it, replacing if necessary (yes Paul, i carry the ruler in my kit bag as well...)...
There I go ASSuming again.:mad: If no round counter exists then spring selection will be more or less subjective.
Pat, would you please, at your convenience, post the max/min specs for the rifle and carbine buffer springs? My search-fu has been weak on this.
For field use, I would have thought you had scribe marks somewhere on your anatomy.;)
Grant-www.sprinco.com is looking for distributors for Tactical Springs LLC Super Duty CAR-15 / M-4 Buffer & Extractor Springs.
ETA: Just got off the phone with Allen/Alan Dugger(sp?) at Springco. He has an M4 buffer (shot-peened, heat-treated and stress-relieved and dunked in something for corrosion resistence and metal enhancement) and an extractor spring (everything but shot-peened because they don't make shot that small) in a hard plastic case for $19.95. He stated the springs were comparable (but probably better) than David Tubb's offering at a lower price. Can't order on the we site yet so call. Don't hold your breath for getting them through Brownells.
Pat_Rogers
07-28-06, 11:56
I don't have my data with me, but i believe the M4 is 10 1/16 to 11 1/4.
M16 is 11 3/4 to 13 1/2.
I'm Irish- it would have to be an extractor spring for it to register on my body...
Alan is a great guy. More importantly, his springs work as advertised.
As you know, you can pay now or pay later, but a buffer spring and extractor spring- especially considering the quality- for twenty bucks can be considered an investment in longevity...
Submariner
07-28-06, 13:44
Thanks, Pat.
Alan has been a very busy man since I posted the info above. Took me a while to get through to order a set for each carbine and a couple spares.
Dave Berryhill
07-28-06, 13:46
I've got nothing against springco/tacticalsprings.com. Quite the opposite - I'm going to be selling their springs. Their springs are excellent, especially their buffer springs.
With that aside, I had an interesting conversation about this subject with one of the small arms engineers at Crane recently. He said that they tried all kinds of different things to improve the extraction reliability of the M4. The tried extractors with multiple springs. They tried moving the location of the extractor pin in order to change the leverage of the extractor spring. The problem is that the extractor spring is short, it only has a few coils and it gets cycled many times in a short period of time. Because of this, all the extractor springs they tested had short lives.
He said that of all the modifications they tried, nothing worked better than adding an O-ring and the black insert. It's a KISS solution that is inexpensive and works. So use quality parts and springs but don't get married to them because they are consumables and replacing them is cheap. Whether you use music wire or chrome silicon springs mady by Wolff, Colt or anyone else, replace them at regular intervals or when you feel they are worn out. Replace the O-ring when it gets worn or torn.
BTW, he also said that they use the standard bolt gas rings in the M4. Not because the 1-piece (McFarland) gas ring is/isn't a better part but because the standard gas rings work fine as long as you replace them when they are worn and because they are a standard part that is already in the system.
Pat_Rogers
07-28-06, 14:03
Hi Dave- Wow, common sense- excellent!
When the "O" ring first came upon the scene there were a bunch that made bad noises- and still do. The bottom line is that the O ring and the black insert (another noisemaker favorite) actually do work.
Which is more then i can say for any of the unenhanced bolts that i have tried....
For about the past year we have been playing with buffer/ extractor CS/moly plated springs from Tactical Springs. The parent company is well known in the competitive shooting world.
I don't have the knowledge, equipment or time to do proper testing- therefore i stick w/ pulling triggers.
I have absolutely nothing negative to say about them. They work.
Are they better/ longer lasting/ attract women with firm American yabbos? Can't say. Do they work at least or better then other springs i have used?
Yes, subjectively.
I run them in those guns that i use, and will let you know if i see any aberrations.
Re PM. I would prefer to change everything out at regulated intervals. Understand Paul what you are saying about cost. Crane is looking at the round counter computer in the PG for exactly those reasons- to ensure necessary parts are changed before failure, and to not change anything unnecessarily.
I keep a ruler on by workbench with buffer spring length (+ and -) for M4 and M16 marked.
On those rare occasions when i do a real deal cleaning i'll remove the spring and measure it, replacing if necessary (yes Paul, i carry the ruler in my kit bag as well...).
I have had Wolff extractor springs go for 7-1k rounds (with the "O" Ring) before problems- too wide a variation and not enough statistical sampling to make any decisions.
Just fyi...
Pat,
Do you have any thoughts or recommendations regarding heavier weight buffers/carriers? Reason I ask is, the way I understand it, by adding weight you delay unlocking and extraction until pressures subside, relaxing the case's grip on the chmaber walls. I'm just wondering if including extra weight in the system eases the extractor spring burden. Any thoughts?
Dave Berryhill
07-28-06, 14:15
Hi Dave- Wow, common sense- excellent...
Yeah, imagine that!
Pat_Rogers
07-28-06, 14:19
I am not an engineer, and i stay at Hampton Inn while TAD/TDY.
Having said that, i run H2 buffers on my guns. It was explained to me as you stated by those who Know More Than I, so i listened.
I have malfunctions on my guns about as often as Haley's Comet passes by, and i'm not sure if it is because of any one thing, a combination of things or my juju is great.
Mods,
What about Sticking this thread for future/newbee reference? I've learned a lot about extraction issues/enhancement just by reading this discussion. Lot of knowledge from true AR conosieurs...
I got an e-mail back from A. Dugger about their springs. He basically states the same thing that ISMI does about spring life and how SS springs wear down. Here are some quotes from him on Spring and buffers:
"Mil-Spec buffer springs are constructed from music wire. The load of a conventional music wire buffer spring is reduced by 25% after only 5,000 cycles. The load is measured in this type of spring as the resistance against compression at two determined heights. The closed load is the measured resistance when the spring is installed, i.e. the height when the bolt is in full battery. The open load is calculated at the height that spring achieves at the maximum compression. This height is quite static because the buffer limits the potential compression in this application. Both loads will degrade in a music wire buffer spring as much as 20% in only one year in a static, unfired state. Heat is also the enemy of music wire. Degradation in performance can be accelerated at temperatures as low as 175 degrees F in cyclic conditions!"
Extractor Spring & buffer FAQ’s:
Q: Should I use a D-Fender / O-Ring / SOPMOD Kit buffer insert with this spring?
A: NO. Do NOT use with D-Fender / O-Ring / SOPMOD Kit buffer insert with this spring. Use a stock (issue) M4 buffer insert. This is an extra power spring and is designed for use with OEM buffer.
Q: What buffer runs best with these springs in select fire?
A: H2 Buffer
Q: Should I use a D-Fender / O-Ring / SOPMOD Kit buffer insert with this spring?
A: NO. Do NOT use with D-Fender / O-Ring / SOPMOD Kit buffer insert with this spring. Use a stock (issue) M4 buffer insert. This is an extra power spring and is designed for use with OEM buffer.
C4
My opinion on buffers goes like this:
H2's for Middy gas systems
H3's for Carbine gas systems
Couple these with a quality CS spring (like ISMI) and you have a more reliable weapon that has less felt recoil.
C4
Roger, different. The #60 "O" rings commonly available would work for a short time in a pinch (and i have used a whole bunch of them on my guns as well as others).
Having said that, we were able to purchase a great quantity of the Crane type at a significant savings....
OK, since we're going to get so deep into this... I've asked before, but no one has ever been willing to divulge what elastomeric compound Crane has specified for the O-ring. I have my suspicions based upon the material properties specified for various compounds as recommended in the Parker O-Ring Handbook and other sources, but I'd like to know for sure what is provided in the Crane kit. Do I have to pay off Fyodor, Dmitri, Ivan, and Alexei, or is someone willing to come out of the closet with this information (or at least contact me via PM)? Many thanks in advance for the feedback.
Pat,
Do you have any thoughts or recommendations regarding heavier weight buffers/carriers? Reason I ask is, the way I understand it, by adding weight you delay unlocking and extraction until pressures subside, relaxing the case's grip on the chmaber walls. I'm just wondering if including extra weight in the system eases the extractor spring burden. Any thoughts?
Inertia is the resistance to the starting and stopping of motion. Basically, the heavier the weight the longer it takes for the carrier to begin to move. However, Inertia includes the stopping of motion too so the heavier you make the bolt/carrier/buffer the more energy is transmitted to the receiver extension.
I personally think the lightest buffer that will run reliably should be used.
That said I like the AAC buffer and think it is good for the money. It is not overly heavy and uses sliding counter weights.
OK, since we're going to get so deep into this... I've asked before, but no one has ever been willing to divulge what elastomeric compound Crane has specified for the O-ring. I have my suspicions based upon the material properties specified for various compounds as recommended in the Parker O-Ring Handbook and other sources, but I'd like to know for sure what is provided in the Crane kit. Do I have to pay off Fyodor, Dmitri, Ivan, and Alexei, or is someone willing to come out of the closet with this information (or at least contact me via PM)? Many thanks in advance for the feedback.
Not Crane, but for a data point here's what Sully has on his website regarding his rings:
Made of Viton - holds up to 600+ degrees fahrenheit and resistant to solvents and chemicals.
There's another piece on his website where he says they withstand up to 400 degrees Farenheit, so not sure what the temp ceiling is, but even 400 degrees seems like there'd be plenty of margin.
Mods,
What about Sticking this thread for future/newbee reference? I've learned a lot about extraction issues/enhancement just by reading this discussion. Lot of knowledge from true AR conosieurs...
Great idea! I PM'd Boom cuz I have no powers in this forum.
Great idea! I PM'd Boom cuz I have no powers in this forum.
Excellent idea its done.
Pat_Rogers
07-28-06, 21:05
Allan mentioned not using an "O" ring with his extractor as it didn't need it.
Having said that, i have an "O" ring on one gun with his extractor spring. The world didn't end, and pigs didn't fly so apparently it isn't major.
I'll let you know how it plays out.
Ned Christiansen
07-29-06, 20:07
Here's my two cents. I've just started trying some Crane O rings (handing them out to students with extractor probs) and they seem to do the deal as well as the D-ring, but I don't have the personal first-hand knowledge of long-term success with them that I do with the D-rings. But I have no problem filling in those blanks with info from guys like Pat and Dean and others, who say they work long-term.
Here's one thing about the D-ring though-- when you open up a gun and find a D-ring, you know it's a D-ring. You find an O ring and it could be the Crane or the Home Depot. I can think of a few scenarios where it might matter.
Dave, I think my extractor testing actually did not include the Wolff spring, I'm thinking it was not out yet at that time. I should get some and see how they stack up, should be fine by all accounts. But I sure did find a wide, wide variance in the amount of pressure it took to compress springs to where they would be in use under the extractor. And wide variances in wire diameter, free length, and number of coils. Sometimes, these variances were within the half-dozen from a given source...... in case anybody doesn't yet realize that the gun makers don't make all their parts (none in some cases).
In my testing I found one set of springs (Les Baer) that were so long and strong that they would go coil-bound (bottomed out upon themselves) and not permit the extractor to snap over without actually flexing a little. I did not run any of these in a rifle without first shortening them a tad. A better spring but too long, it left me wondering if the LB AR's had some accommodation for the longer spring like a deeper pocket in the extractor or a recess in the bolt body.
I was sceptical about O and D rings. I felt they might give too much extractor tension and cause malfs when the extractor is snapping over a rim, and/or, we would see extractors break from flexing due to the added push at the back. I have never seen nor heard of either, while I've seen many, many a rifle go from bad to good with the addition of either.
Have run my guns without O or D rings just as an ongoing test of the extractor springs that have "passed" my test for tension, and they've been fine. Just added a Crane O ring to one, maybe 1K rounds ago, to see if good heavy spring plus O-ring would cause any probs, and none.
Dave Berryhill
07-29-06, 21:16
Good stuff to know Ned. Both Wolff and Springco/Tactical Springs say not to use an O-ring but I have yet to hear of anyone having a problem with too much extractor spring tension. If someone has, please speak up!
While the engineer from Crane said that all the extractor springs that they tested failed to maintain tension relatively soon, he didn't say what springs they tested nor did he quantify how many rounds "soon" was. I got the impression that the O-ring really becomes the primary spring or is as important as the coil spring for the carbine.
Pat_Rogers
07-29-06, 21:47
Ned- you are correct that it could be an ersatz "O" ring vice the real deal.
From a practical standpoint we once did go to the local store and but a bunch of #60 when we had issues and no real "O" Rings. They worked through several thousand rounds, and while i can't comment on long term longevity they solved the immediate problem.
Dave- Alan says not to use them because he was advised not to use them by a very experienced shooter. He stated that "My only perspective was based on a recommendation by X". "If the "O: ring works, all the better".
I have a whole bunch of Wolff extractor springs w/ "O" rings that work fine, and haven't seen a single issue with using them together.
Of course, YMMV under certain circumstances etc.
The round count to failure for springs, bolts (unless you believe the hype from a particular manufacturer of a different system) is clearly subjective, and the variables are enough to make trained statisticians weep (so i'm told).
I am happy that Ned has taken the time to look deeply into this, though i imagine his frustration overload light must be shining brightly!
Add to this the great number of makers who apparently substitute lesser parts for real, and i can see this being an exercise in futility.
Dave- your last sentence it telling, and may have hit the nail squarely on the head.
Ned Christiansen
07-29-06, 23:52
Been wanting to try this-- no spring, "D" or O-ring only, no spring. I'm thinkin' it'll work, might get a chance to try it this coming week.
Been wanting to try this-- no spring, "D" or O-ring only, no spring. I'm thinkin' it'll work, might get a chance to try it this coming week.
Please note that we(MGI) recommend that the D-Ring(D-Fender) have the spring in place, so as to act as a locating device to keep the D-ring in the proper place, and this would also be the case with O-rings. You are correct in your assumption that the ring takes up the primary duty, when placed in this application. In the case of the D-Fender, it is engineered to provide 4x the normal extractor tension.
During the extensive testing of these items back in the 1990's, when Mack Gwinn and Jim Sullivan were partners in introducing this whole concept, it was found that migration of the ring could cause failures, and in some cases severe enough to seriously "tie-up" the weapon from firing. This can also happen when a ring breaks, and the repeated extractor motions move it around to where it isn't supposed to be.
This is a main reason why Mack and Jim did not just release an O-ring, which they did plenty of testing with, and proceeded to the "D" shaped design with the wedge profile for better reliability. It was presented to Crane, and tested, and actually they never got one to fail in their extended testing.
Now, I realize that plenty of people use O-rings, and they work. They work to varying extents, and the reason Mack and Jim switched was because they found it virtually impossible to predict whether the O-ring would have an early failure or a longer life, in any given application. Some failed early, and some went along pretty well, and some went a long time, and it didn't matter what material they tried. They were not satisfied with this unpredictability. The "D" shape is purposely made to overcome these problems, and that is why the shape is the most important part of this device.
Crane went with the O-ring because of cost, and their statement to Mack and Jim when the decision was made, was that they could just give out a pocketful of them, so if they failed, a new one could be then installed.
Now, it can be debated all day what anybody prefers to use, but this is the actual history of this type of device, that was spoken to me right out of the mouth of the guys who invented, pioneered, tested, and presented this form of device for the first time. And Mack Gwinn and Jim Sullivan are not rookies at gun design. Even if some of you might not know who Mack Gwinn is(original founder of Bushmaster, no longer associated with them, designed the M2 .50HB-QCB quick barrel change system for FN, designer of the original early Bushmaster SMG, current designer of the MGI Modular AR15 system, among numerous other things along the way), certainly you all must be familiar with Jim Sullivan, who worked at a very high position in the original AR15 design team with Gene Stoner.
So you can pay your money and take your chances with whatever you want to use. I at least can say that you are all now duly informed on how these items came to be used, what the history of the development was, and the conclusions that were arrived at after testing by the inventors(who probably know just a little bit about this subject).
:)
Dave Berryhill
07-30-06, 13:01
...Crane went with the O-ring because of cost, and their statement to Mack and Jim when the decision was made, was that they could just give out a pocketful of them, so if they failed, a new one could be then installed...
I don't doubt that nor does it conflict with what the Crane engineer told me. I hope you don't think that anyone here has intended to denigrate your product. Frankly, I find the history and development of these kinds of things fascinating and I appreciate your sharing that story.
It makes sense to keep the coil spring so that the D/O-ring is held in position.
Ned - you might try using the weakest coil spring you can find just to do this. It might be interesting to see a comparison of these - one with just an O-ring and one with an O-ring and weak coil spring - just to see how much it affects the life of the O-ring.
Submariner
07-30-06, 14:38
The round count to failure for springs, bolts (unless you believe the hype from a particular manufacturer of a different system) is clearly subjective, and the variables are enough to make trained statisticians weep (so i'm told).
Mean Time Between Failure: Prediction process, whereby an estimate in operating hours (or here, rounds fired) is calculated of an assembly's component(s) to perform its/their intended function. This is the objective standard for reliability testing.
ADM Rickover dragged the Navy into the era of reliability testing to prove the safety and endurance of nuclear propulsion systems. Testing to a standard isn't cheap; yet, the Navy (and Crane is Navy) has that institutional knowledge regarding such testing. Given the comment that Crane is looking for a good round counter, that would seem to be the direction they are heading.
This is a main reason why Mack and Jim did not just release an O-ring, which they did plenty of testing with, and proceeded to the "D" shaped design with the wedge profile for better reliability. It was presented to Crane, and tested, and actually they never got one to fail in their extended testing.
...
Crane went with the O-ring because of cost, and their statement to Mack and Jim when the decision was made, was that they could just give out a pocketful of them, so if they failed, a new one could be then installed.
...
So you can pay your money and take your chances with whatever you want to use. I at least can say that you are all now duly informed on how these items came to be used, what the history of the development was, and the conclusions that were arrived at after testing by the inventors(who probably know just a little bit about this subject). :)
twl-"Better reliability..." In Mack and Jim's reliability testing, what did they determine the MTBF of the D-ring to be compared their (hopefully comparable Crane-type) O-ring? Hype and fear (you pays your money and takes your chances) are marketing tools, not reliability testing. With these numbers, sample size and testing protocol, we see how the inventors came to their conclusions and have the same level of confidence as you. Then we can decide if increase in reliability, if any, is worth the additional cost.
Ned - you might try using the weakest coil spring you can find just to do this. It might be interesting to see a comparison of these - one with just an O-ring and one with an O-ring and weak coil spring - just to see how much it affects the life of the O-ring.
Or even a broken extractor spring to determine if the o-ring not only enhances performance but provides system redundancy.
twl-"Better reliability..." In Mack and Jim's reliability testing, what did they determine the MTBF of the D-ring to be compared their (hopefully comparable Crane-type) O-ring? Hype and fear (you pays your money and takes your chances) are marketing tools, not reliability testing. With these numbers, sample size and testing protocol, we see how the inventors came to their conclusions and have the same level of confidence as you. Then we can decide if increase in reliability, if any, is worth the additional cost.
The O-rings tested by Mack and Jim, prior to moving into the D-Ring design, had an unpredictable MTBF, between several dozen rounds, and several thousand rounds. I'm sorry that I can't be more exact than that, but I can't get Mack on the phone right now. The issue that was perplexing them was that they could find no way to determine accurately when the things were going to fail, because they didn't seem to exhibit predictable behavior in these circumstances. That's why they went the route that they did.
According to the DTC certification letter dated 7 May 2001 that I have here on the D-Fender, it states that reliability was "ALWAYS improved" and "with NO negative effects", when "extensively tested on 3 forms of M16/M4 weapons", by Crane. According to Mack, the Crane tests proceeded over about a year's time, during which time they tested the D-Ring to several tests of over 30k rounds each, and never did get a failure. Apparently they decided that about 100k rounds of ammo was enough to expend on this testing. That's the information that I got from Mack.
The armorer for the San Bernadino County Sheriff's SWAT Team, has documented a million rounds on their D-Fenders, in primarily full-auto use. He emailed Mack a letter stating this, and approved that we may provide this information for our use, and that he can be contacted at his department to verify it. They use the D-Fenders and the RRB buffers, and both hit the million round mark in their documented use. Remember, this is his statement, not mine. I'm just relaying it here.
Here's his contact info, from the signature line of the letter he sent regarding this documentation.
Bruce D. Park, Sheriff's Armorer
San Bernardino County Sheriff's Department
Public Safety Regional Training Center
Armory
18000 Institution Road
San Bernardino, CA 92407
To be on the conservative side, we recommend changing the D-Fender when you replace your bolt. We have seen very few, but there have been a few, D-Fender breakages, and they were sent back to us, and unfortunately the users could not give us any round counts, or other circumstances which may have led to the few failures we have seen. We generally attribute these to an improper installation of putting the spring on top of the D-Fender, instead of thru the hole in the D-Fender. We replace D-Fenders if there are any breakages with them, at no charge.
But, to answer your specific question, no MTBF for the D-Fender has ever been determined, because nobody to date has reached enough rounds to make a repeated determination that it will fail at that round count.
As I mentioned above, we conservatively rate it at the life of the bolt, and recommend changing then.
Anyone who wants to try their own test to wear one of these things out, just make sure that you have plenty of ammo on hand.
The quote from the DTC Certification letter states, "Documented use of these rings has occurred at NSWC Crane over the last year in an attempt to develop the limits of their performance". It seems to me that the words, "in an attempt", backs up Mack's statement that the attempt to find the limits was not reached, and the recommendation to SOPMOD was generated. There were no limits reached in the test that were mentioned in that DTC certification letter, and I have the letter sitting here in my lap right now as I'm quoting off of it.
We just received payment Friday for a large D-Fender order to the British SAS unit.
I spoke with a SF soldier from the 5th Group in Ft. Campbell yesterday, and he verified that his unit is using D-Fenders, to me by phone just yesterday morning, during his order for another different product from us.
Our D-Fender is not "totally pervasive" throughout the militaries, but it is in use by the thousands, and has been for a number of years. It is usually procured by individual unit discretionary funds, and mostly by the special-ops groups.
We don't make these guys buy our stuff, and apparently they want it. They can get the O-rings as issue, which would not cost anything to them specifically. They replace these O-rings with our D-Fender.
So, we have a good product that is getting some recognition and use.
We also realize that the O-ring works, and for many people it is a perfectly good choice for their range work or training activities, and it is much less costly.
Mack is a SF 5th Group vetaran of MAC-V-SOG, and highly decorated with many tours in VietNam. His son(Mack III) who also works with the company is a veteran of the SF 7th Group, as a weapons man for 15 years, and sniper instructor. They know what it means to depend on your weapon. They are the company owners.
Personally, it makes little difference to me what any person wants to use in their gun. I primarily posted this stuff here, because I watch these discussions take place, time and again, with all kinds of speculation, and questions about what polymer should be used, and which # O-ring they should by at the plumbing store, etc.
I thought that a little firm information from a historical perspective, with how's and why's would be helpful to the members.
:)
Pat_Rogers
07-30-06, 18:44
Thanks for the info- if fills in a lot of blanks.
Thanks also for not taking unverified info and putting it out as factual. One mil rounds primarily on FA doesn't resonate real well, but i guess is possible.
Other makers- on other forums- have taken less and caused a lot of problems for themselves.
I appreciate yoyr time in doing this.
Submariner
07-30-06, 20:27
Re: DMS Technology Center (DTC):
The Diminishing Manufacturing Sources (DMS) Technology Center at Crane Division-Naval Surface Warfare Center was designated as the Naval Surface Warfare Centers (NSWCs) leader and center of technical expertise on DMS issues in 1996. As an overall goal of providing Life Cycle Sustainment for any given system, the DMS Technology Centers approach is to integrate analysis processes to identify current availability; obsolescence; supply; reliability; installation and improvement schedules; operating and support costs problems, and to provide viable economic solutions. The goals of this effort are to:
Reduce acquisition time and costs, and increase affordability while maintaining mission readiness.
Reduce life-cycle support costs while increasing availability
Mitigate the implementation risks of transitioning state-of-the-art technology, and reduce total ownership costs of Department of Defense (DOD) systems, which in turn increases their Return on Investment (ROI).
So their conclusion, based on a cost-benefit analysis rather than reliability alone, would seem to be in line with their charter:
Crane went with the O-ring because of cost, and their statement to Mack and Jim when the decision was made, was that they could just give out a pocketful of them, so if they failed, a new one could be then installed.
"[S]everal tests of over 30k rounds each" with no failure is a very small sample size. Was that several tests of 30,000 rounds on one D-fender in each of several tests or several D-fenders tested for 30,000 rounds in each of several tests? Having said that, it may be a clue as to its reliability. Some folks shun gold because federal reserve notes are readily available and work just fine; others buy gold. ;) Famous Naval Saying: "If the minimum weren't good enough, it wouldn't be the minimum." Thanks for the information.
Thanks for the info- if fills in a lot of blanks.
Thanks also for not taking unverified info and putting it out as factual. One mil rounds primarily on FA doesn't resonate real well, but i guess is possible.
Other makers- on other forums- have taken less and caused a lot of problems for themselves.
I appreciate yoyr time in doing this.
Agree with Pat. Good stuff and thanks for taking the time to clarify.
C4
Thanks guys!
I'm glad that you found the information helpful in adding some insight into the extractor enhancement issue.
Regarding the million rounds, I also have to say that came as a surprise to us, and we received that letter unsolicited from Sheriff's Armorer Bruce Parks.
He presented this to us, says he has the documentation from his department usage records, and is willing to back up what he says, to verify.
Coming from an LE official, I'm considering that valid user testimonial.
We do not make any claims of anything like that in our ads or promotions, and was mentioned here purely in response to the MTBF questions raised about the D-Ring, as additional testimonial to our other documentation from Crane, and source quoted for verification purposes.
I appreciate the opportunity to get this information out, so that members can benefit from as much information on the subject as possible.
Pat_Rogers
07-31-06, 08:34
The million rounds is not the issue- the FA is. I have observed that SWAT Team at training and they are very much GTG. I have not seen them use FA in my very limited observations, but then again i have seen a pig fly.
The million rounds is not the issue- the FA is. I have observed that SWAT Team at training and they are very much GTG. I have not seen them use FA in my very limited observations, but then again i have seen a pig fly.
Okay.
Because I don't wish to put words into the man's mouth, or create any problems by paraphrasing or taking anything out of context, so that all can read exactly what he wrote to us, here's the letter in its entirety:
--------------------------------------------------------------------------------------------
"Mack,
I wanted to do a follow-up on our conversation from the other day. Enclosed is a photo of the firearm that I told you about. This Firearm is used by the
Sheriff's training Division for Demonstrations, Ammo Evaluations, and Officer
Qualifications. As I told you on the phone about two weeks ago this firearm
reached the 1 million round count. Normally this would not be a big deal
for us as we have many firearms that have exceeded that number of rounds. The amazing fact that we have not had to do any repairs to this firearm to reach this milestone is the reason that I am writing to you.
We installed your buffer system and a D-Fender ring into this firearm about a
year ago. This firearm had already been in service for at least five years with
an unknown number of rounds through it.
We have done nothing more than routine cleaning and lubing to this firearm during this time period.
As a demo gun this firearm routinely is fired full auto for multiple magazines
with no cool down returned to the locker only to be used again without cleaning or lubrication. Normally for an AR style rifle to achieve this round count for us it would have to be rebuilt at least once or twice.
I attribute this lack of rebuilding of this firearm directly to the buffer and
D-Fender ring that we bought from you. As I told you we were so happy with the results of our evaluation we purchased these items for all our SWAT team members M4 machineguns. The ability to control the firearms in full auto sold the team members on the Buffers. The added reliability was just an extra benefit that they liked after the fact.
Again I just wanted to say thanks for getting me to try your product. Keep up
the good work."
Bruce D. Park, Sheriff's Armorer
San Bernardino County Sheriff's Department
Public Safety Regional Training Center
Armory
18000 Institution Road
San Bernardino, CA 92407
------------------------------------------------------------------------------
Please note that the letter states that the firearm under discussion had an " unknown number of rounds through it", which indicates that the million round count must have been started after these parts were installed, or else the round count would still be unknown.
I cannot account for some of the stated issues about maintenance or rebuilding, because certainly there must have been some routine replacements of various parts in the gun during that time. Perhaps breakages was what he meant, but I don't know.
What I know is that this letter came in from him after they'd been using some of our parts for quite some time. What you see above is the letter as it came to us from him.
The words are his, and if any issue is to be taken with those words, it would be best to use his contact info to allow him to clarify any points of contention.
At any rate, the letter is posted for informational purposes for the members, and anyone can accept it or reject it, as they see fit. I consider it a "user testimonial" from an LE source , and that's as far as I take it. We do not make any claims that our products will make your gun "magic". We claim good reliability, and suggest reasonable replacement guidelines with our products. What's here is a user testimonial letter from a credible source, with contact info to verify any of his statements with the source.
And please note that it does say that they bought the items, and we did not give stuff away in "trade" for a promotional letter for us.
As a general rule, we are not "hoaxed" or lied-to by members of the LE community, and especially when they sign their name and give their department contact info, and give permission for them to be contacted. So, there you have it. FWIW.
Pat_Rogers
07-31-06, 09:45
Thanks, and i truly appreciate the efforts you have taken to avoid the pitfalls that others seem to be seeking.
Submariner
07-31-06, 10:05
I never did like alphabet soup.:mad:
From twl in response to my question re: DTC
The letterhead states:
Department of the Army
Headquarters, US Army Developmental Test Command
314 Longs Corner Road
Aberdeen Proving Grounds MD 21005-5055
I assume that the DTC acronym is short for "Developmental Test Command".
The body of the letter begins:
Memorandum for Department of the Navy, NSWC Crane Division, Code 4081, B-2521 SOPMOD Project Office, ATTN: Mr XXXXX [edited for PERSEC], 300 Highway 361, Crane IN 47522-5001
"Subject: DTC Safety Confirmation of the D Ring.
1. Purpose: This memorandum is to provide a DTC Safety Confirmation for the D Ring elastomeric washers to extractors of M4/M16 series weapons for USSOCOM Forces." and the letter continues on thru the comments about the testing and conclusions, which include:
"5. ............. Based on the test information provided by NSWC, Crane Division, a DTC Safety Confirmation is issued for the use of "D-Fender" 'D" Rings on M4/M16 series weapons.".
It is dated 7 May 2001
Signed by:
XXXX XX XXXXXXXXX [edited for PERSEC]
Chief, Tank Automotive Armaments Division
Directorate for Test and Technology
I hope this helps to provide some of the information that you want.
Regards,
twl [edited fopr PERSEC]
MGI
Thanks.
My springs are from SAW. I get the rings for free from a friend. I have a few I can send your way. Professor, send me a PM.
how bout your brother from another mother?
where's the love bro???
see ya soon kisara
meat
QuietShootr
08-08-06, 18:50
My opinion on buffers goes like this:
H2's for Middy gas systems
H3's for Carbine gas systems
Couple these with a quality CS spring (like ISMI) and you have a more reliable weapon that has less felt recoil.
C4
I run Colt 9mm buffers in my carbines, along with a Crane o-ring and SAW spring, and ISMI buffer spring. I have had fantastic reliability with this setup.
Chris Poston
09-03-06, 13:35
deleted
I know this post is a little late in the game, there is a great wealth of knowledge in this post but I have a question.
What do ya'll recommend as "reliability" upgrades to the ar, buffers, extractor aids etc?
I know this post is a little late in the game, there is a great wealth of knowledge in this post but I have a question.
What do ya'll recommend as "reliability" upgrades to the ar, buffers, extractor aids etc?
Honestly... other than sticking with quality parts from known makers/dealers, and the particular items listed in this thread, the best reliability upgrade I can think of is good ammo. I see more problems from crappy super low budget el cheapo ammo than parts hands down.
A couple of points of trivia:
1) In a recent NSWC-Crane solicitation for M4A1 and Mk 18 Mod 0, the replacement cost of the O-ring was listed as $0.01. (N00164-06-R-4805)
2) Judging from an Army publication, the current rifle extractor spring insert is also black. However, it does not use the same extractor spring as those issued with current M4.
Rifle: NSN 1005-01-424-5899
Carbine: NSN 1005-01-505-2886
(PS: The Preventive Maintenance Monthly: Dec, 2004)
3) Back when the extractor spring insert was introduced, a side benefit was found that it significantly increased the life of the extractor spring. (New and Improved Rubber Compounds for Weapon Systems. Oct 1972. Rock Island, IL: Army Weapons Command, General Thomas J Rodman Laboratory.)
A couple of points of trivia:
1) In a recent NSWC-Crane solicitation for M4A1 and Mk 18 Mod 0, the replacement cost of the O-ring was listed as $0.01. (N00164-06-R-4805)
2) Judging from an Army publication, the current rifle extractor spring insert is also black. However, it does not use the same extractor spring as those issued with current M4.
Rifle: NSN 1005-01-424-5899
Carbine: NSN 1005-01-505-2886
(PS: The Preventive Maintenance Monthly: Dec, 2004)
3) Back when the extractor spring insert was introduced, a side benefit was found that it significantly increased the life of the extractor spring. (New and Improved Rubber Compounds for Weapon Systems. Oct 1972. Rock Island, IL: Army Weapons Command, General Thomas J Rodman Laboratory.)
Good stuff! I buy my O-Rings directly from the factory that supplies them to the Military. I wish that I paid .01 for them.
C4
Glockster35
11-13-06, 15:39
All,
What a wealth of information this thread has been. I have tried to read every post in this thread, and I think I am still lost. Maybe I missed the conclusion somewhere.
I will not be firing full auto with my rifle, so are these upgrades necessary for reliability in my rifle?
I have a 14.5" barreled flat top upper and an A2 20" inch style upper, both with their own bolt assemblies.
These uppers are used on the same lower for the time being. I want to maximize reliability with both of these uppers. Are there different recommendations for extractor upgrades for the different uppers, or would similar parts work for both of these assemblies?
Does Grant sell the entire upgrade kit for one price? Are they on his website?
I looked on Brownells and this is all I found:
AR-15/M16 EXTRA POWER EXTRACTOR SPRING (Wolff) #969-000-032
AR-15 EXTRACTOR BUFFER (Brownells) #078-000-071
AR-15/M16 D-FENDER D-RING (MGI) #741-015-003
(I couldn't locate an O-Ring for the AR15)
I think I will be purchasing 4 full kits...2 to use now, and 2 for backups!
not trying to be a pain in anyone's ass, I honestly couldn't get a conclusion!
All,
What a wealth of information this thread has been. I have tried to read every post in this thread, and I think I am still lost. Maybe I missed the conclusion somewhere.
I will not be firing full auto with my rifle, so are these upgrades necessary for reliability in my rifle?
I have a 14.5" barreled flat top upper and an A2 20" inch style upper, both with their own bolt assemblies.
These uppers are used on the same lower for the time being. I want to maximize reliability with both of these uppers. Are there different recommendations for extractor upgrades for the different uppers, or would similar parts work for both of these assemblies?
Does Grant sell the entire upgrade kit for one price? Are they on his website?
I looked on Brownells and this is all I found:
AR-15/M16 EXTRA POWER EXTRACTOR SPRING (Wolff) #969-000-032
AR-15 EXTRACTOR BUFFER (Brownells) #078-000-071
AR-15/M16 D-FENDER D-RING (MGI) #741-015-003
(I couldn't locate an O-Ring for the AR15)
I think I will be purchasing 4 full kits...2 to use now, and 2 for backups!
not trying to be a pain in anyone's ass, I honestly couldn't get a conclusion!
You can install all components (spring, black insert and Crane O-Ring in your A2 or 14.5). I do sell them as a complete kit here: http://www.gandrtactical.com/cleaning.htm
C4
So when using the d-fender do you also have to use the insert as well?
Robb Jensen
01-10-07, 00:14
So when using the d-fender do you also have to use the insert as well?
You should. Teh D-fender/Crane O-ring isn't designed to replace the insert, it's to enhance what power is already there.
So when using the d-fender do you also have to use the insert as well?
You may use the insert if you wish.
It's not required when using a D-Fender, but it won't hurt anything either.
The D-Fender adds 4x the extractor tension, so it makes whatever little difference that comes from the insert a moot point. The D-Fender works just fine when used with a plain ol' standard spring, but if you feel better about doing upgrades to the spring and insert, you can do it.
I personally use a standard spring with no insert, and a D-Fender, on my own gun, and I have no extraction issues with any barrel lengths or gas system lengths that I install into my QCB(quick-change-barrel) upper.
Is an o-ring or d-fender good to put on an extractor in a rifle length gas system? Am I correct that the army now mandates a black insert, uprgraded spring, and o-ring on their M4's? Is there any upgrade for the M16A2?
Is an o-ring or d-fender good to put on an extractor in a rifle length gas system? Am I correct that the army now mandates a black insert, uprgraded spring, and o-ring on their M4's? Is there any upgrade for the M16A2?
I don't think I would do anything other than upgrade the extractor insert and springs in an A2.
C4
Shawn Dodson
03-13-07, 13:11
P/N ORV-006, available at http://www.smallparts.com/products/descriptions/orv.cfm
Shawn Dodson
FirearmsTactical.com
P/N ORV-006, available at http://www.smallparts.com/products/descriptions/orv.cfm
Shawn Dodson
FirearmsTactical.com
Similar, but different. They were a stiffer material. Quick shipping, but $12 for a small package via FedEx (despite the request to use USPS).
Just wanted to say thank you to the people who posted such good info. There is always someone out there in the universe who has already plowed the ground and knows what you need to know, but the trick is to find them.
I hope I have the answer to my FTE, and it looks like I have it triangulated. I definitely have a better idea of what the right questions are now.
Just flat outstanding.
I purchased the BCM kit and installed the HD spring. I had a lot of trouble getting the extractor back on with the spring and the "o" ring - so just went with the spring right now.
Is there a trick to getting it all back together with the "o" ring in place? Or do I just need stronger fingers? :)
I purchased the BCM kit and installed the HD spring. I had a lot of trouble getting the extractor back on with the spring and the "o" ring - so just went with the spring right now.
Is there a trick to getting it all back together with the "o" ring in place? Or do I just need stronger fingers? :)
They can be a PITA. Make sure the spring is fully seated in the extractor (use needle nose plyers). Then, make sure that the holes are ligned up properly between the extractor and the bolt. Put the bolt on something soft (like a rubber mat) and take a non-marring hammer and drive the pin in.
C4
hahagobangbang
04-08-07, 16:51
twl,
I've been using the D-Fender for awhile now and am perfectly happy with such an effective, user friendly product. Keep up the good work.
Does the LMT DEFENDER 2000 M4 14.5 with Semi auto Standard Carrier/MP bolt
Come already with the correct inserts/spring etc!
Came Direct from LMT
BTW
My Brasss Flys to the right and over shoulder 10 ft or more in a neat little pile
I also use a 9mm buffer
Im sold on the 9mm buffer
After years of thinking it was BS
My other Bushy/ LMT M4 has a H buffer and there is a bigg difference
Does the LMT DEFENDER 2000 M4 14.5 with Semi auto Standard Carrier/MP bolt
Come already with the correct inserts/spring etc!
Came Direct from LMT
BTW
My Brasss Flys to the right and over shoulder 10 ft or more in a neat little pile
I also use a 9mm buffer
Im sold on the 9mm buffer
After years of thinking it was BS
My other Bushy/ LMT M4 has a H buffer and there is a bigg difference
The LMT bolts come with black inserts and Crane O-Rings.
9mm buffers are made for 9mm AR's while they can work, you could run into a problem as the internal weights are not seperated. You want your weights going in the same direction. Sometimes in 9mm buffers, the weights are not all going the same way and it causes malfunctions.
If you want the same weight as a 9mm buffer, get an H3.
C4
The LMT bolts come with black inserts and Crane O-Rings.
9mm buffers are made for 9mm AR's while they can work, you could run into a problem as the internal weights are not seperated. You want your weights going in the same direction. Sometimes in 9mm buffers, the weights are not all going the same way and it causes malfunctions.
If you want the same weight as a 9mm buffer, get an H3.
C4
Thanks for the info I had ne IDEA about RRA Newer 9mm buffer
Yes I wanted the H3 but cost alot
I got RRA second model of the 9mm
It has weights in it but I dont know how many? its all Black one piece with Green rubber at the end
Is this the same 9mm that you are talking about
Grant
Also Grant Ive only had the Defender now for a year and have around guessing over 1500rds without any problems?
Do H3 wiegh more than the newer RRA 9mm buffer
thats what I get for saveing cash
Thanks for the info I had ne IDEA about RRA Newer (mm buffer
Yes I wanted the H3 but cost alot
I got RRA second model of the 9mm
It has weights in it but I dont know how many? its all Black one piece with Green rubber at the end
Is this the same 9mm that you are talking about
Grant
That is a 9mm buffer and is what I am talking about.
C4
Also Grant Ive only had the Defender now for a year and have around guessing over 1500rds without any problems?
Do H3 wiegh more than the newer RRA 9mm buffer
thats what I get for saveing cash
H3 and 9mm buffers weigh the same.
If the 9mm works for you then great! In SOME cases they cause a problem.
C4
H3 and 9mm buffers weigh the same.
If the 9mm works for you then great! In SOME cases they cause a problem.
C4
So Far it works? Its still Kinda new yet UNDER 2000rds
It would be better to avoid TROUBLE Like you STATED
Thank for your Help on this
After adding “H” buffers and BCM kits to the extractors on my 723 clone and my M4gery, I’m headed out this morning to function test both rifles. I’ll post back my results.
ETA: Just got back. Both weapons functioned great with the BCM upgrade and Crane o-rings. I also like the slight reduction in recoil with the “H” buffer!
After adding “H” buffers and BCM kits to the extractors on my 723 clone and my M4gery, I’m headed out this morning to function test both rifles. I’ll post back my results.
ETA: Just got back. Both weapons functioned great with the BCM upgrade and Crane o-rings. I also like the slight reduction in recoil with the “H” buffer!
Good deal!
I cant tell between the H buffer and standard buffer? in my WEAPONS
Matter of Fact my Bushmaster lower /VLTOR and LMT M4 14.5
Kicks like a Bitch! I need a rubber pad and a H3
My Defender 2000 SOPMOD M4 Stays on Target SO MUCH BETTER
I use the 9mm buffer! RUNS 100% and its so heavy
9mm buffer part # 0107
Whats strange is the Bush/LMT spits the brass out about a foot
and the defender 2000 over to the right and behind over 10 feet
But Like GRANT Stated!! I will be switching to a H3 its the same weight but extra wiegts
toddackerman
07-20-07, 14:09
How do we get a hold of Sully please?
Tack
This is the part. With shipping I had to pay almost 10 cents each.
http://www.mcmaster.com/nav/enter.asp?partnum=9464K11&pagenum=3271
I was thinking the same thing. Those viton ones should well outlast any buna-n ones.
I called Crane looking for the material and was told they are Viton.
Well, then, there you have it. I'm not saying anybody here is in the wrong, and I'm not trying to be a cheap bastard, but a package of 100 o-rings made of the same material for a price of $5.55 plus shipping beats $10 or more per one any day. I realize and agree that some things shouldn't be skimped on, but if the D-rings are made of the same material, then the only difference becomes the shape. I doubt this will make a big difference in the purpose of the ring in the first place. It is a wear part either way. If I am wrong, I am sure someone will point out why. At least I hope so.
Ok, I read through all seven pages and have a quick and simple question; where can I quickly get 100 black inserts and springs (not Wolff)?
Thanks
Ok, I read through all seven pages and have a quick and simple question; where can I quickly get 100 black inserts and springs (not Wolff)?
Thanks
I can help with extractor inserts, but don't have 100 CS springs. If you want regular SS springs, I can help with those.
C4
I can help with extractor inserts, but don't have 100 CS springs. If you want regular SS springs, I can help with those.
C4
Grant, thanks for the quick response, I'll pm you over the weekend and get it set up.
I don't know about the springs, but I got the o-rings from an industrial supplier. MSC www.mscdirect.com has the viton o-rings in the #6 size in a pack of 100. If you don't say anything, it'll be shipped overnight (their standard method) for $8. If you're not in a hurry, and ask nicely, they might drop it in the mail instead. I got the package for $8.50, delivered. 100 viton o-rings 1/4" od by 1/8" id.
Just a few options for extractor spring upgrades.
Left to right: Buffer Tech, Wolff, Colt, BCM.
More. (http://www.weaponevolution.com/forum/showthread.php?p=2623#post2623)
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/group.jpg
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/ColtD-Ring.jpg
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/BCM3.jpg
Texpatriate
03-26-09, 22:32
What extractor spring-o-ring/no o-ring-buffer combination would be best to run in a 6.8 SPC mid-length?
I currently have the rifle length blue buffer in there now, but I'm assuming it would be good to upgrade it with one of the BCM upgrade kits. But considering that it is a mid-length, would it best not to use the included crane o-ring? Or would the increased recoil of the 6.8 necessitate the use of the o-ring? Thanks.
What extractor spring-o-ring/no o-ring-buffer combination would be best to run in a 6.8 SPC mid-length?
I currently have the rifle length blue buffer in there now, but I'm assuming it would be good to upgrade it with one of the BCM upgrade kits. But considering that it is a mid-length, would it best not to use the included crane o-ring? Or would the increased recoil of the 6.8 necessitate the use of the o-ring? Thanks.
I would go with a 4 coil and a black extractor insert. The O-Ring is your call.
C4
I would go with a 4 coil and a black extractor insert. The O-Ring is your call.
C4
What he said. Run it with the 4 coil spring and black buffer and if it functions run with it. If not I would upgrade to the 5 coil spring before the O-ring and run it 5coil and BB. If that dosent do it for you put back the 4coil and try it with O-ring. And if your still having problems go all out. However the 4coil and BB should be more than sufficient.
Has anybody had any expierences were they felt the need for CRANE bolt upgrades in a 6.8 mid-length?
Has anybody had any expierences were they felt the need for CRANE bolt upgrades in a 6.8 mid-length?
The Crane upgrades were designed for guns with carbine gas systems (espeically the 10.5 types).
Since middy guns do not run as fast and hard as SBR's, I do not believe that you need to the 5 coil spring and Crane O-Ring. I still like to use the black extractor inserts though.
Now if your 6.8 is over gased (which is entirely possible) and you are having extraction issues, you might want to look at adding an O-Ring.
C4
Is anyone familiar with M&A (http://www.mgimilitary.com/store)? I found the D fender and spring parts at a decent price but the product detail does not say who makes or what their springs are made of. If I replaced the springs and added the D ring would I be good to go?
I wrote to M&A and they replied. My original message to them is at the bottom. Their answer seemed kind of vague to me. Is spring steel with a black insert and a D fender adequate for a reliability upgrade or should I go with Wolff springs or another kit? Do I just need to replace the ejector spring and add a D fender or O ring? Or should I replace everything on the bolt carrier?
On Feb 09, 2010, at 1:43 PM, Info @ M&A wrote:
They are spring steel. We use military contractors.
Thank you / Have a great day
----- Original Message -----
From: LongRider
To: info@mapartsinc.com
Sent: Tuesday, February 09, 2010 2:58 PM
Subject: Contact Form From mapartsinc.com
The extractor / Ejector spring products listed at http://www.ar15m16.us/products.asp?catId=75&subOne=345&subTwo=385 does not indicate who makes them or what they are made of. Could you please enlighten me as to who makes them and what they are made of. Thank you for your time and consideration
M&A parts has been discussed here before. I would stick with a quality manufacturer when it comes to extractor springs/ inserts, etc...
I wrote to M&A and they replied. My original message to them is at the bottom. Their answer seemed kind of vague to me. Is spring steel with a black insert and a D fender adequate for a reliability upgrade or should I go with Wolff springs or another kit? Do I just need to replace the ejector spring and add a D fender or O ring? Or should I replace everything on the bolt carrier?
On Feb 09, 2010, at 1:43 PM, Info @ M&A wrote:
M&A parts has been discussed here before. I would stick with a quality manufacturer when it comes to extractor springs/ inserts, etc...
Thanks for the heads up read the whole thread and must of missed it
You can't identify extractor springs by the number of coils. The drawings do not even specify the number of coils except as a reference which is variable. That means the spring maker tests the spring and adjusts the coils and OAL to achieve the lbs of force that is specified on the drawing. Also, each brand may use its own wire thickness and a different OAL.
I just measured every extractor spring Brownell's sells. I can say there is some scary stuff there.
The USGI spring from 1971 had a stress/strain ratio under 50% when compressed to 0.112. Those can last 18,000+ rounds. True, they only have 4 lbs of force at this height, but the o-ring will add in the extractor tension without having to resort to an extra power spring.
Why is an extra power spring bad? Because more force means more stress. Some of the springs from Brownell's had stress/strain ratios above 80%! If you monkey around with extra power springs, then change them every 1500 rounds.
The new M4 spring that is Copper colored is pretty interesting. It has exactly double the force of the earlier spring but does not have a huge amount of additional stress. If I were going to run a spring without an o-ring, I would use the new Colt M4 spring.
Or use an old-style 0.022 wire diameter USGI (people call this the '4 coil') with an o-ring and it should last the life of the bolt (but since it is cheap, might as well change it at 5000 rounds).
Now here is why I feel Chrome Silicon magazine, action, and extractor springs are BS:
A magazine with the standard 17-7 stainless spring may be stored fully loaded with 30 rounds indefinitely. Note that Chrome Silicon springs will not resist taking a set better than MIL-STD 17-7 magazine springs. A spring 'takes a set' when it reaches the proportional fatigue limit. The higher the tensile strength, the more it can resist taking a set. Here are the material properties of three premium materials*:
Chrome Silicon:
Minimum Tensile Strength: 235-300 psi
Max Operating Temp: 475F
Fatigue Properties: Fair
Music Wire ASTM A228
Minimum Tensile Strength: 230-399 psi
Max Operating Temp: 250F
Fatigue Properties: Excellent
17-7 PH Stainless
Minimum Tensile Strength: 235-335 psi
Max Operating Temp: 650F
Fatigue Properties: Good
As you can see, all three materials are about the same with the main difference being temperature, corrosion, resistance, and price. 17-7 costs 2.75 times as much as chrome-silicon ** so it only makes sense to give up the corrosion resistance if the price is much lower and you are not worried about rust.
The CS spring makers would have to believe they have something new and better and that the military is just behind the times or penny-pinching for not using it. That is not true, as CS is far cheaper than stainless springs. The reason the military has not changed is likely because they have actual engineers who work with facts.
*
http://optimumspring.com/technical_reso ... _wire.aspx
http://optimumspring.com/technical_reso ... _wire.aspx
http://optimumspring.com/technical_reso ... _wire.aspx
http://www.docstoc.com/docs/4884305/Typ ... CIFICATION
**
Fundamentals of Spring Design from the Spring Manufacture's Institute, page 13, table SM-8
So, who sells the Gold (Colt) springs? ;)
Brownells may have them. I got mine from Specialized Armament at the last Phoenix gun show.
So, who sells the Gold (Colt) springs? ;)
Brownells SKU # 160-304-025 (http://www.brownells.com/.aspx/sid=10818/pid=0/sku/Extractor_Spring_Assembly)
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/Coltsmall.jpg
Jay Cunningham
08-06-10, 08:07
There is something to be said about buying an LE6920 and not ****ing with it.
if your stick works.. it works. Most times silly add ons not needed. Seldom with rifle or middy.
In initial SOCOM use "crane" o'ring often used on regular m16 bolts & extractor springs (not m4a1), more easily ordered through the mil system, on 10.3/10.5" CQBR uppers & 14.5" often with suppressors. A nice quick fix for extraction problems on an nearly over-gassed fast reciprocating shorty. These guns often also had early gas port erosion from rough firing schedules and use of frangible ammo.
If you want 200 at a time.. you can get the correct O'rings from LMT
Correct o-rings:
http://www.mcmaster.com
1201T16
While the o-ring may not be "needed" on mid or rifle guns they are used on the Mk12.
We use the rifle spring and o-ring on all our rifles from 7.5" up to 20", 5.56 and 6.8 without any issues.
I have done some full auto testing in a 10.5" with an old SP1 extractor spring with the white buffer and an o-ring, ran like a champ. I don't worry about the an extra power extractor spring or buffer color with an o-ring.
Agreed. Blue/black insert are both fine.
And this cannot be over-stated. It is not that you don't "need" an extra-power spring if you have an o-ring, but extra-power springs are actually bad because they are more likely to break. So the way to think about it is that the o-ring saves you from having to resort to a high-stressed spring.
Once you have the o-ring to add tension, the goal should be to use the lowest-stressed spring, which should give the longest life.
BufordTJustice
08-11-10, 00:06
It is not that you don't "need" an extra-power spring if you have an o-ring, but extra-power springs are actually bad because they are more likely to break. So the way to think about it is that the o-ring saves you from having to resort to a high-stressed spring.
Without starting an argument, how did you come to this conclusion? How I understood it, just because a spring is stronger, doesn't mean it is under more stress. I could be wrong. But I know that Colt's new gold colored extractor spring is 'extra power' compared to what it's replacing..... and that the .mil has tested it to many thousands of rounds more than the weaker spring it replaced. I'm not an engineer.....im just trying to wrap my head around the issue.
Just measure up the spring and put it into spring design software.
The new Colt spring seems to double the force without having that much more stress. So if I wanted to use an extra-power spring, I would pick the Colt design. I would never use it with an o-ring.
The HK 416 spring is not extra-power and seems identical to the old Colt spring.
By the way, I put the USGI rifle-length action spring into spring design software and it claimed it would last for a million cycles. Not sure if that is correct or not. The important thing from that is the action spring is not under-designed and so there is no reason to look for ways to improve it. 17-7 is the best material for it due to corrosion resistance. You could do A228 music wire or certified (not commercial) chrome-silicon if you painted the spring. The software thought either would make it last 10 million cycles.
By the way, a sure-fire way to know if your action spring is out of spec is to remove your upper and put the lower on a scale. Balance it so it stands by itself. Zero the scale. Push on the center of the buffer buffer until it just starts to move. Replace the spring if you have less than 5.3 lbs of force on the scale. 5.8 is normal. More than 6.3 is out of spec.
haha ah HA ha.. holy bat dung! Bathroom scale AR metrics, that is a new level of AR-nerdery, nice!
What has worked for me on Operationall standard gas system M4/shorty & I'm not paying for the parts, new:
-bolt 5K (see failures on rough firing schedules at 8-14k)
-action spring 5k
-barrel 10-15K, or gas port elongates &/or cyclic changes, &/or when won't group at 2-300
I'm sure some bean counter would have a chart of inefficiency for this replacement matrix, however I can't remember when I had an issue that wasn't magazine related.
Life cycle cost using legacy... Bolt $35, action spring $2, barrel, $175... I would suspect cheaper and less backside pain than buying HK416 or whatever new phaser & dealing with their O&M BS.
BTW the HK416 action springs I have had my claws on (replacement uppers) are definitely stiffer than the standard ones that were in the legacy lowers.
I use a digital postal scale.
Yes, the 416 action spring has fewer coils than the M4 spring. It is stiffer. I just did the scale test on a 416 and got 8.0 lbs (for when the buffer just starts to move - if you move it an 1/8 of an inch it might read 8.2 or 8.4 lbs).
And maybe that type of spring offers some advantage. I would consider that.
The buffer is the same weight as an H2 buffer (within a few grams - both are 130-132 or so grams or around 4.6 - 4.7 oz).
Sierrahotel83
08-11-10, 15:52
I am lost, I thought this thread is about extractor spring and inserts? How are we now comparing buffer springs.
Scotter260
08-11-10, 17:26
So,
-Colt spring AND O-ring/D-Fender
-or-
-Colt spring AND nothing?
So,
-Colt spring AND O-ring/D-Fender
-or-
-Colt spring AND nothing?
I would say for your normal M4 (14.5 inch), 16 carbine, 16 mid-length, and 20 inch rifle, use JUST a Colt-spec spring with black insert.
For something shorter than 14.5, or something with pistol-length gas, use a new Colt-spec spring...
OR....
An old-spec spring (0.022 wire) and an o-ring. These older springs are called "4-coil" but if you look at the drawing, there is no requirement that they be made 4 coils. Rather, they have to meet a force-spec. That is why they sometimes have more or less than 4 coils. This should last even longer than the new Colt-spec spring and provide even more force.
At no time would I use a new-spec Colt spring with an o-ring as the force will probably be too much and if you have an o-ring you might as well use the lower-stress older spring.
Scotter260
08-11-10, 19:49
Thank you sir.
I see Bravo Co. has a kit so I'll go with a 3-pack of those.
Elementary but on the same topic, with what frequency should extractor springs, etc. be changed? Extractors themselves?
Thank you again.
Some HD springs I would change every 1500 rounds. A new type Colt spring I would change at 5000 rounds. I know of the traditional springs that made 18000 rounds but they are cheap so why risk it unless you just shoot for fun and it doesn't matter.
Very hard core users should replace the entire bolt assembly every 5000 rounds (sell the old one on AR-15). Less hard core use perhaps at 10,000 rounds. Recreational shooters should just replace it when it fails.
Thank you sir.
I see Bravo Co. has a kit so I'll go with a 3-pack of those.
Elementary but on the same topic, with what frequency should extractor springs, etc. be changed? Extractors themselves?
Thank you again.
It is a HD spring - so should not be used with an o-ring.
To re-iterate - either a new Colt-spec spring and no o-ring, or an old Colt-spec spring and an o-ring. Their design may be outstanding. I just don't know because I don't have the specs. The Colt specs have been tested and approved by the military so I worry less about it.
SW-Shooter
06-02-11, 19:33
It is a HD spring - so should not be used with an o-ring.
To re-iterate - either a new Colt-spec spring and no o-ring, or an old Colt-spec spring and an o-ring. Their design may be outstanding. I just don't know because I don't have the specs. The Colt specs have been tested and approved by the military so I worry less about it.
This topic is relevant to my interests so I resurrected it.
The comment in red is not quite 100% accurate. BCM states it may or may not be necessary.
Great thread and info. Thanks
SlayerG2-1
08-14-11, 21:40
Anyone have any experience with the Tanks Rifle Shop o-ring? I use a Crane in my middy, but the Tanks are $3.99 for five of them on Brownell's and I just wanted a few for my toolbox for friends. Thanks in advance for any info.
Continued from
https://www.m4carbine.net/showthread.php?t=93930&page=6
Which spring is good?
Gold/Five Coil.
Black insert, and possibly a Crane O-ring.
I never felt comfortable referring to spring by the number of coils when the drawing says that the number of coils is a REF and it changes from batch to batch.
I ran spring analysis software on pretty much all extractor springs in the Brownell's catalog. The newer military gold one was not bad but still over-stressed (over 45% of MTS). There are some absolutely horrifyingly bad extractor spring designs in some of 'your' favorite bolts (I don't mean you specifically, lamarbrog). Some were at 80% of MTS.
I was not able to buy the spring that I wanted in the AAC bolt - had to have it made. Basically, the AAC spring is the original M16 spring design (which is not overstressed). Except I had them made from MountJoy brand Rocket Wire to make it even lower % of MTS, and then the extraction force was raised to carbine standards without adding additional stress to the spring by the o-ring.
I pull all other springs out of bolts, including the newer gold military ones.
There is this $700 spring design software that I use:
http://www.smihq.org/public/software/asd6.html
All of the extra power extractor springs that are popular - I bought them and put them into the software - and it flags them as outside of good engineering practice.
The original M16 spring, however, was clearly designed by someone who knew what they were doing, as the software says it is great and has stress within normal limits.
The problem is, carbines need more extractor force than the M16, so the original M16 spring is not quite good enough. There are two ways to solve it - use a stiffer spring (but then they are over-stressed because, given the tiny cavity they sit in, wire of a desirable thickness will no longer fit for these springs with more force) - or use an o-ring with the original spring.
The o-ring is the correct solution, and not a gimmick - as it is the only solution where you get more extractor force without a spring design that is over 45 percent of the material's tensile strength.
We went one step further, and made the original spring out of higher grade wire - Rocket Wire, but did it without making it stiffer, so the higher grade material serves simply to make it last even longer.
Very interesting. What are the repercussions of using a spring that is over-stressed? It just wears out faster? Breaks?
The O-ring is a modification that I absolutely believe in for carbines. My personal rifle is currently a 20" with rifle gas system (by choice, I specifically sought that configuration) so it is not of major concern to me... I use the 3-coil spring and a black insert. (And I don't think this is a genuine black insert... feels too soft.)
This is really neat information, I'm glad you're so open about sharing it.
Yet the o-ring has been repeatedly found to result in excessive extractor tension in real use.
With an original M16 rifle extractor spring?
I can't figure out why anyone would put an o ring on a rifle extractor spring in stead of just replacing the rifle spring with the 5 coil spring and Black/Green insert. :confused:
The rifle spring is the only one which has stress of less than a 45% of MTS.
Springs must not be referred to by the number of coils because they are reference values and change from batch to batch, even for the same design.
Just spring or spring and buffer?
I am asking if you think that an original M16 rifle spring, with an o-ring, and an insert - would have too much extraction force on an M4. Or if you just meant that that combination with a spring that was not an original M16 rifle spring would have too much force.
Is there a force spec at the extractor groove?
Too much is bad and too little is bad.
The standard springs must have a force spec, but what about the combination of the spring and o-ring?
I've got nothing against springco/tacticalsprings.com. Quite the opposite - I'm going to be selling their springs. Their springs are excellent, especially their buffer springs.
With that aside, I had an interesting conversation about this subject with one of the small arms engineers at Crane recently. He said that they tried all kinds of different things to improve the extraction reliability of the M4. The tried extractors with multiple springs. They tried moving the location of the extractor pin in order to change the leverage of the extractor spring. The problem is that the extractor spring is short, it only has a few coils and it gets cycled many times in a short period of time. Because of this, all the extractor springs they tested had short lives.
He said that of all the modifications they tried, nothing worked better than adding an O-ring and the black insert. It's a KISS solution that is inexpensive and works. So use quality parts and springs but don't get married to them because they are consumables and replacing them is cheap. Whether you use music wire or chrome silicon springs mady by Wolff, Colt or anyone else, replace them at regular intervals or when you feel they are worn out. Replace the O-ring when it gets worn or torn.
BTW, he also said that they use the standard bolt gas rings in the M4. Not because the 1-piece (McFarland) gas ring is/isn't a better part but because the standard gas rings work fine as long as you replace them when they are worn and because they are a standard part that is already in the system.
I read this thread hoping to figure out why Noveske states this on their site:
6. What extractor spring should I use?
Your Noveske rifle comes with a "4 coil" rifle extractor spring and O-ring. This combination provides the extractor tension needed for reliable extraction in a carbine with a longer service life than some "extra power" extractor springs. Do not use an "extra power" extractor spring with an O-ring, this can cause too much extractor tension and keep the extractor from clipping over the rim. The color of the extractor buffer is not a concern when using an O-ring.
I am glad that I read this thread instead of randomly picking a nice looking place and hurling the question into cyber-space, sans research. It makes a lot of sense that rubber maintains it's "bounce" better than the metal spring, especially whatever "special" rubber they are using. Tons of O-ring material out there.
Anyway, thanks for this information, and as always, glad I bought what I consider "the best". Noveske knows their stuff and this answers part of where that knowledge came from. Thanks again for your post!
This, coupled with rsilver's data makes infinite sense as to why Noveske does this. Looking forward to running it hard at my first carbine course, later this year. All the faith in the world in it, I just enjoy learning.
Thank you sir.
I see Bravo Co. has a kit so I'll go with a 3-pack of those.
Elementary but on the same topic, with what frequency should extractor springs, etc. be changed? Extractors themselves?
Thank you again.
I used one of these in a 16" carbine gas system and had several FTE issues. I replaced it with a kit from tactical springs and the problem disappeared, this is the set up I run in my 14.5" middy now. A little on the expensive side but I don't mind paying for things that work.
remington79
08-31-12, 19:22
[QUOTE=rsilvers;726132]You can't identify extractor springs by the number of coils. The drawings do not even specify the number of coils except as a reference which is variable. That means the spring maker tests the spring and adjusts the coils and OAL to achieve the lbs of force that is specified on the drawing. Also, each brand may use its own wire thickness and a different OAL.
I just measured every extractor spring Brownell's sells. I can say there is some scary stuff there.
The USGI spring from 1971 had a stress/strain ratio under 50% when compressed to 0.112. Those can last 18,000+ rounds. True, they only have 4 lbs of force at this height, but the o-ring will add in the extractor tension without having to resort to an extra power spring.
Why is an extra power spring bad? Because more force means more stress. Some of the springs from Brownell's had stress/strain ratios above 80%! If you monkey around with extra power springs, then change them every 1500 rounds.
The new M4 spring that is Copper colored is pretty interesting. It has exactly double the force of the earlier spring but does not have a huge amount of additional stress. If I were going to run a spring without an o-ring, I would use the new Colt M4 spring.
Or use an old-style 0.022 wire diameter USGI (people call this the '4 coil') with an o-ring and it should last the life of the bolt (but since it is cheap, might as well change it at 5000 rounds).
Thanks for that bit of info. I didn't know that about the copper colored spring. My LE6920 has the black insert and copper colored spring. It does not have any type of O-ring or Defender in it. So far, so good. It spits the brass out in a consistent manner about 10 feet away. It also has an H buffer. I have no plans to change anything unless its with the same thing for maintenance.
Sorry about the way the quote came out. I hit the quote button and this is the way it came out.
Anyone know where I can buy the "original" rifle extractor springs? Everywhere I look I can only find extra power springs.
sinlessorrow
08-31-12, 22:36
Anyone know where I can buy the "original" rifle extractor springs? Everywhere I look I can only find extra power springs.
I have had no luck finding them, that said I would just stick to the new Colt "Gold" extractor spring, its probably the best there is currently.
I am pretty sure that TACOM announced years ago that the extractor springs would all be the newer style across the board. That being the case what sinlessorrow said makes sense. Don't chase the elusive golden dragon when it's not necessary.
sinlessorrow
08-31-12, 23:19
I am pretty sure that TACOM announced years ago that the extractor springs would all be the newer style across the board. That being the case what sinlessorrow said makes sense. Don't chase the elusive golden dragon when it's not necessary.
You are correct. What bothers me is why do they call it gold? It is certainly copper colored.
http://quib.weaponevolution.com/Assorted/Ex%20Spg%202.jpg
See copper.
http://i203.photobucket.com/albums/aa273/SinlesSorrow/Mobile%20Uploads/IMG_5620.jpg
In an earlier post in this thread there was a quote from Crane that none of the extractor springs they tested maintained full force for very long and the O-ring ended up being the spring.
I wonder if the O-ring or the D-fender would work OK using the Gold Spring without the black insert? It seems like the force might be too great with both the insert and an O-ring.
One should generally not use a O-Ring with a Colt copper spring. The extractor may not be able to clear the cartridge head when you drop the bolt.
Anyone know where I can buy the "original" rifle extractor springs? Everywhere I look I can only find extra power springs.
Brownells has them.
rsilvers: do you have a part number for the correct spring? Under Colt parts my catalog lists the same spring for carbine and rifle and It looks like it is the Gold Spring. I couldn't tell from the descriptions if any of the other ones were the original strength.
Thanks
sinlessorrow
09-01-12, 15:56
rsilvers: do you have a part number for the correct spring? Under Colt parts my catalog lists the same spring for carbine and rifle and It looks like it is the Gold Spring. I couldn't tell from the descriptions if any of the other ones were the original strength.
Thanks
SP64026
That part number SP64026 appears to be the Gold Spring.
Thanks anyway.
BufordTJustice
09-03-12, 20:50
I'm putting my ****ing helmet on...so here goes:
Aside from projections and calculations on a computer screen, has anybody actually tested these springs after, say 5K rds of use for strength, OAL, etc?
Numbers in a program are nice...but field testing is the only way to know for sure.
I, for one, will continue to use and recommend BCM & Springco CS extractor springs. I have dozens of buddies in my agency now using the BCM springs on 16" Bushmaster carbines with coming close to 7k on two of the guns (they are on specialty teams). They do not use the o-rings and they are still running strong. I'm meeting one of them at the range tomorrow. None of their guns ran well until they moved up to H-buffers and the BCM kits sans o-ring.
I'm sure the Colt 'gold' spring works perfectly well also...but I don't see any real-world evidence that the BCM & Springco springs are as 'defective' as they seem on paper.
Rsilvers, I'm not an engineer, so I lack any of your knowledge on the subject. I'm also not challenging your calculations....I have no doubt that you have done them correctly and that they are mathematically correct. I'm just stating that my real-world experience does not line up with the massive fail that these two springs are predicted to be via your software.
Here are the part numbers for Brownells .022 diameter wire and 4 coil extractor springs (original rifle spec springs):
078-000-086WB AR-15 Extractor spring OEM spec 3 PK $2.79
Same thing in Chrome Silicon steel
078-000-104WB AR-15 Extractor spring Chrome Silicon 3 PK $2.99
I just received several of these springs and they measure right. I plan on using them with black inserts and D-Fender rings on all of my ARs. If this doesn't work out I will fall back to the Springco extractor springs.
I have tried the D-Fender rings with heavy extractor springs and the extractor travel was much too limited and heavy IMHO (didn't shoot this setup). This setup feels about right and the D-Fender ring provides quite a bit of damping which should help correct any extractor bounce.
Not the right place I'm sure but what setup does anyone run with the .300 AAC Blackout? I ask because it's my next build.
Just an update to this topic. I have between 2,000 and 2500 rounds on this bolt. It is a Noveske 4-coil w/ O-ring setup. It has performed flawlessly. HOWEVER...I don't like what I see here, and so I am replacing it with the Colt "Gold" spring and leaving the O-ring off. I feel better about that.
The end of the extractor is actually "cutting into" the O-ring. I generated this image using my flatbed scanner. The other side of the O-ring (which faces the body of the bolt) is new-looking. I can't help but think that this reduces the tension provided by the O-ring in the dynamic environment in which it lives, and I wonder to what extent/at what point it matters, but the Colt "Gold" spring should fix things nicely, I would think. The 40,000 round test by "Lucky Gunner Labs" explains that they replaced the cheap bushmaster extractor springs at 5K rounds with this spring, as the BM springs were causing FTE's. By 10K rounds, the carbines were still running great with the Colt springs.
http://i50.tinypic.com/2qbvig7.jpg
At the 5,000 round mark, the bolt carriers, upper receivers, and barrels were cleaned. After observation of high speed video showed inconsistent cycling, action springs ($3) were replaced, as were extractor springs ($6.99) and gas rings ($2.19).
....
Average OEM extractor springs should be replaced beginning at 2,500 rounds and no later than 5,000. Better extractor springs will not require such frequent replacement with any ammunition – the Colt “Gold” extractor springs used in each rifle starting at 5,000 rounds were still providing reliable extraction at the 10,000 round mark, and would not have required replacement after 5,000 rounds.
http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/
Sparky5019
04-28-13, 09:39
Ok...I've read this whole thread several times over the last few years and I'm starting to have a question.
I use CS 4 coil springs from Tactical Springs w/ black insert and Viton Crane O-Rings in my 14.5" middy. I am now retaining my brass and reloading it.
Would one do better to stay with this set up or upgrade to a CS 5 coil w/ black insert and no O-Ring to minimize rim damage (assuming no FTF/FTE)?
Thoughts?
Sparky
Dave Berryhill
04-28-13, 11:07
...Would one do better to stay with this set up or upgrade to a CS 5 coil w/ black insert and no O-Ring to minimize rim damage (assuming no FTF/FTE)?
Thoughts?
Sparky
For a few bucks you could try it and report your results here.
Sparky5019
04-28-13, 11:17
Dave, I was thinking about doing just that...
I'm pretty slammed at the moment so was looking for opinions too.
I'll let y'll know what I found out! It might be a while though.
Sparky
BufordTJustice
04-28-13, 14:07
Ok...I've read this whole thread several times over the last few years and I'm starting to have a question.
I use CS 4 coil springs from Tactical Springs w/ black insert and Viton Crane O-Rings in my 14.5" middy. I am now retaining my brass and reloading it.
Would one do better to stay with this set up or upgrade to a CS 5 coil w/ black insert and no O-Ring to minimize rim damage (assuming no FTF/FTE)?
Thoughts?
Sparky
I use the 5-coil (springco's original "extra power spring"). I think the 4-coil is the reduced power rifle spring and it is the one they recommend for people who reload their brass.
Also, a heavier buffer like the Vltor A5 system helps go easy on brass as well.
I recently switched over to the Colt spring. I did this because my current setup (14.5" middy w/rifle spring and O-ring) was chewing the O-ring up after a few thousand rounds. Performance seems identical regarding flawless function, and ejection-pattern. The Colt "gold" spring is great design that is fundamentally well executed, mechanically. I recommend them and put them in all of my friend's guns. From the MK to the A4, its what is currently spec'ed.
You don't need the O-ring. People need to look at why this issue came about, those who were shooting and what they are shooting. Not one of my AR's needs an O-ring to extract and function properly.
Ok...I've read this whole thread several times over the last few years and I'm starting to have a question.
I use CS 4 coil springs from Tactical Springs w/ black insert and Viton Crane O-Rings in my 14.5" middy. I am now retaining my brass and reloading it.
Would one do better to stay with this set up or upgrade to a CS 5 coil w/ black insert and no O-Ring to minimize rim damage (assuming no FTF/FTE)?
Thoughts?
Sparky
Colt 6920, about 1,000 rounds through it, on a recent cleaning noticed no O ring, just the "gold" spring with black insert. Do I need the O ring? Seems to run fine, no extraction issues. I've read through this thread and am confused as to whether or not I need this ring or not. What extraction problems could arise with or without O ring? Did it ship without the O ring, or did I loose it?
Thanks
sinlessorrow
02-16-15, 22:57
Colt 6920, about 1,000 rounds through it, on a recent cleaning noticed no O ring, just the "gold" spring with black insert. Do I need the O ring? Seems to run fine, no extraction issues. I've read through this thread and am confused as to whether or not I need this ring or not. What extraction problems could arise with or without O ring? Did it ship without the O ring, or did I loose it?
Thanks
You have not needed the O-ring since late 2007 when Colt got the copper spring through military testing. Some springs need O-rings, but HD springs do not and the copper spring is the standard issue HD spring.
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