View Full Version : Softer recoil impulse.
polymorpheous
09-04-10, 07:46
Just recently I had the opportunity to shoot the FN SCAR16.
The thing was a pussycat.
Softest shooting 5.56 I ever shot.
The recoil impulse felt like it went straight back.
I want to emulate this characteristic in my M4gery.
I understand a little about how everything functions together...
Buffer, action spring, BCG, gas port.
Right now I'm running a DD 14.5" CHF barrel with a pinned A2X flash hider.
So this already limits me... Can't use a different muzzle device.
My BCG is BCM.
The whole receiver extension assembly is BCM.
The buffer weight is "H".
I don't know the gas port diameter on the barrel.
It cycles the low powered Russian ammo just fine.
Not a single hiccup.
But the recoil impulse is up and to the left.
I want to soften this up so the felt recoil goes straight back.
CaptainDooley
09-04-10, 08:32
My understanding is that a heavier buffer/stiffer spring with soften the felt recoil impulse, but I'm fairly certain you'll need a comp/brake to affect muzzle control. There may be options I'm not aware of, but the above is what I've seen so far.
FWIW, part of what helps the SCAR is the extra 16 oz. it carries around. It is also a slower recoil impulse. If you watch the charging handle move it goes much slower than the bolt on an AR.
Heaver buffer and spring in the AR will help some, as will obviously shooting lower-pressure ammo. I can tell a distinct difference in Wolf and quality brass cased ammo.
I have this upper (http://www.bravocompanyusa.com/BCM-14-5-Mid-Length-Upper-Receiver-VTAC-TRX-p/bcm-urg-mid-14%20vtactrx11.htm) with a PWS FS556 brake on it and it is by far the most controllable AR I've ever shot, perhaps with the KAC SR15E3 coming in neck and neck.
Failure2Stop
09-04-10, 09:21
Did the SCAR you shoot have the PWS comp on it?
I have quite a few rounds through the SCARs, and I find the SCAR-L to be much bouncier than an M4 when both are wearing A2-ish FHs.
The methods to reduce bounce in the M4 is to increase buffer weight and action spring weight, and add a good comp. I have yet to fire a weapon that has better in-line recoill characterisitcs than an AR. Stick a PWS DNTC comp on an 18" Noveske SPR barrel with an H2 buffer and a UBR with a DD RIS II, and you will know the definition of "minimal sight deviation". From what I hear, the BCM 14.5 Middies with H2/H3 buffers are highly controllable, and adding a PWS makes them even better.
Really, it isn't hard to get an M4 to beat a SCAR in this department.
I have been using a 9mm buffer in my middie for about 2 years now. I can honestly say I don't know if it really does anything as far as felt recoil. I don't know much about inertial mass affecting recoil, but i sometimes think the 9mm buffer smooths out the action, but at the back of the recoil cycle it almost seems to have more recoil.
Moving more weight albeit at a slower speed, seems to me to produce about the same recoil. i use the heavier buffer to help with wear on parts, etc...not necessarily the felt recoil.
There are two camps of "controlling" recoil by varying mass and spring weight.
The heavier slower.. which is exactly that, slower and more easily perceived. This feels less sharp to most people. Some will notice a more pronounce initial (buffer at end of travel) and secondary(locking back into battery) recoil impulse with heavy mass approach. Not even approaching AK bad, but noticeable.
Or the lighter, less mass, lightened carriers and lighter buffers, which of course quite literally cycle faster, and with an attuned shooter, can drop split times. As would be expected by speeding things up, there are more reliability considerations with this approach.
A compensator is, of course, very effective in a smallbore high velocity rd spitting out gas as the 5.56. With a perm attached comp your not going to be able to experiment with muzzle devices easily.
polymorpheous
09-04-10, 10:58
Thanks for the replies fellas!
The SCAR did indeed have the PWS comp on it.
Changing my muzzle device isn't really an option for me.
At least without sending my one and only upper to ADCO.
I mostly shoot a lot of Tula ammo.
$4 a box.
It short-cycles my buddy's LMT upper.
My next upper will more than likely be a 16" BCM middy.
This will open up my options quite a bit.
I guess my question is:
Given my current set-up, not knowing my gas port diameter...
What set up would help me get closer to an inline recoil?
Specifically buffer and spring?
Thomas M-4
09-04-10, 11:21
You can try a LMT enhanced carrier the timing and gas ports are optimized for the 14.5'' barrel with the carbine gas system also it weights a little bit more than the standard carrier.
I run a H-buffer and standard rate sprinco buffer spring.
The comp on the SCAR is the reason the gun felt so different and more "in-line". You can look into the PWS, AAC brakeout, Battle Comp, etc to get a similar recoil impulse and reduce muzzle rise. A good smith should be able to remove your A2X and swap it out. That combined with a heavier buffer will make a big difference.
Spring and buffer are going to be incremental improvements at best. Not enough to bother with IMHO. Especially given that you can wind up going the other direction and causing malfunctions in a gun that hasn't had any yet.
The primary reason the scar recoils soft is because of the brake
Magic_Salad0892
09-04-10, 15:44
14.5'' .063'' Midlength Gas System.
KAC Triple Tap Compensator.
H3 buffer + Sprinco Extra Powered Spring.
77 gr. 5.56 NATO
^ Feels like a rimfire conversion, I LOVE it. I think this is what markm runs. Sans KAC comp, and Sprinco spring.
Spring and buffer are going to be incremental improvements at best. Not enough to bother with IMHO. Especially given that you can wind up going the other direction and causing malfunctions in a gun that hasn't had any yet.
I disagree. Going to an H2 buffer and a Tubb spring (or to a lesser extent the Wolff XP spring) made a big difference to me in carbines and midlengths, and you can see it on high speed.
I actually think that overall, the action spring, buffer, and a good stance will do more to help the weapon recoil well than just switching the muzzle device.
Then again, I think gas port diameter plays a big role as well ;)
Spring and buffer are going to be incremental improvements at best. Not enough to bother with IMHO. Especially given that you can wind up going the other direction and causing malfunctions in a gun that hasn't had any yet.
I've used Sprinco's "blue" springs on midlength ARs and "red" springs on carbines, with buffers ranging from 2.9 to 5.4 oz, and as long as it will fully cycle (ie not short-stroke.....very important), there is a noticeable reduction in recoil.
I don't mean to bash the OP, but I often wonder about what people are expecting with regard to an AR's recoil. Just because it's .223 caliber doesn't mean it's going to recoil like a .22LR. After all, 120-pound men all over the Third World haven't had much of an issue with 7.62x39 recoil.
polymorpheous
09-04-10, 18:26
I disagree. Going to an H2 buffer and a Tubb spring (or to a lesser extent the Wolff XP spring) made a big difference to me in carbines and midlengths, and you can see it on high speed.
I actually think that overall, the action spring, buffer, and a good stance will do more to help the weapon recoil well than just switching the muzzle device.
Then again, I think gas port diameter plays a big role as well ;)
Thanks. This is the info I am looking for.
I think my stance is pretty solid.
A friend of mine recorded a video of me doing a mag dump with a 10.5" upper.
While I'm no HSLD operator, I seemed to control it pretty well.
I was thinking on a "H2" buffer.
Maybe research the ST-T2 buffer.
Fairly inexpensive.
But I am completely ignorant on action springs.
Hell, I don't even know what type came with my BCM stock set.
polymorpheous
09-04-10, 18:33
I don't mean to bash the OP, but I often wonder about what people are expecting with regard to an AR's recoil. Just because it's .223 caliber doesn't mean it's going to recoil like a .22LR. After all, 120-pound men all over the Third World haven't had much of an issue with 7.62x39 recoil.
Why wouldn't I want to be able to make a faster follow up shot.
Why wouldn't I want to reduce my split time?
Why wouldn't I want to put 3 rounds downrange in the par time for 2 rounds?
Do you see where I'm going with this?
BTW: I can handle the recoil just fine.
14.5'' .063'' Midlength Gas System.
KAC Triple Tap Compensator.
H3 buffer + Sprinco Extra Powered Spring.
77 gr. 5.56 NATO
^ Feels like a rimfire conversion, I LOVE it. I think this is what markm runs. Sans KAC comp, and Sprinco spring.
Really? I was expecting them to run small but not that small. Whats the weakest ammo youve run on the above config?
I bought the brake the owner of a local fun store recommended for my AR-15 and it is pretty amazing how well it keeps the muzzle down. The recoil impulse is almost straight back. I'm forgetting the name now, but I've seen it in a Dillon catalog... of course I just threw my last one away.
Thanks. This is the info I am looking for.
I think my stance is pretty solid.
A friend of mine recorded a video of me doing a mag dump with a 10.5" upper.
While I'm no HSLD operator, I seemed to control it pretty well.
I was thinking on a "H2" buffer.
Maybe research the ST-T2 buffer.
Fairly inexpensive.
But I am completely ignorant on action springs.
Hell, I don't even know what type came with my BCM stock set.
I did a high speed video comparison of SCAR and AR recoil, including a "bad stance" SCAR shot and a "good stance" SCAR shot.
Fast forward to 1:50 -
http://www.youtube.com/watch?v=qTJ8OcOcsWw
Enjoyed the video... very interesting. What type of camera do you use to get hi-speed video like that?
BufordTJustice
09-05-10, 03:44
Polymorpheus,
See my post # 209 on this page:
https://www.m4carbine.net/showthread.php?t=56626&page=11
I feel it will adequately answer your questions.
The buffer weight increase (and buffer spring power increase) will be more readily noticeable when you use an overgassed AR (My buddy has a 16" carbine gas CMMG piston gun in 5.56). I' e been experimenting with H2 and soon H3 buffer sin his rig. The bitch shot almost as hard as my Stamped steel AKM clone in 7.62x39mm....it was anything but smooth. But slap in a Springco blue CS buffer spring and an H2 buffer...the gun suddenly becomes more controllable and exhibits less muzzle rise. It even dings his brass less (he reloads).
I run an H3 + a tubbs flatwire in my 16" BCM middy. I love it. I don't think it's quite as smooth as a 14.5" middy (haven't shot them back to back), but it's damn close. Mine runs great on the .223 tula you speak of.
I also run a PWS FSC556. AND a FA BCG. The gun is a system...all the parts play a role. I have become a HUGE fan of heavier reciprocating masses.
Watch 87GN's vidz and you'll see the light...the proof is in the high-speed-video puddin'. ;)
CAVEAT: Guns are like kids...every single one of them is different. You gotta find what your gun will run well...your identical upper may not run with my buffer spring and H3....maybe it will. Only your field testing will confirm reliability and function. Anyways, reading the entire thread I posted above would be very helpful for you.
Today MarkM and I were shooting the BCM 14.5" middy with PWS flash hider using some of my Hornady 55gr. TAP (steel case). He was using the H3 buffer. It felt like the carbine was firing in slow motion. Everything cycled fine, but there was an instance of failing to lock back.
Unfortunately we didn't have any chance to use hotter NATO ammo but again it was very smooth.
I think H2 is probably the limit. As I stated before if I had unlimited amounts of milspec ammo I would probably run that H3 all the time.
polymorpheous
09-05-10, 07:41
I did a high speed video comparison of SCAR and AR recoil, including a "bad stance" SCAR shot and a "good stance" SCAR shot.
Fast forward to 1:50 -
http://www.youtube.com/watch?v=qTJ8OcOcsWw
That's what started this thread!:laugh:
Great reviews BTW.
polymorpheous
09-05-10, 07:45
Polymorpheus,
See my post # 209 on this page:
https://www.m4carbine.net/showthread.php?t=56626&page=11
I feel it will adequately answer your questions.
The buffer weight increase (and buffer spring power increase) will be more readily noticeable when you use an overgassed AR (My buddy has a 16" carbine gas CMMG piston gun in 5.56). I' e been experimenting with H2 and soon H3 buffer sin his rig. The bitch shot almost as hard as my Stamped steel AKM clone in 7.62x39mm....it was anything but smooth. But slap in a Springco blue CS buffer spring and an H2 buffer...the gun suddenly becomes more controllable and exhibits less muzzle rise. It even dings his brass less (he reloads).
I run an H3 + a tubbs flatwire in my 16" BCM middy. I love it. I don't think it's quite as smooth as a 14.5" middy (haven't shot them back to back), but it's damn close. Mine runs great on the .223 tula you speak of.
I also run a PWS FSC556. AND a FA BCG. The gun is a system...all the parts play a role. I have become a HUGE fan of heavier reciprocating masses.
Watch 87GN's vidz and you'll see the light...the proof is in the high-speed-video puddin'. ;)
CAVEAT: Guns are like kids...every single one of them is different. You gotta find what your gun will run well...your identical upper may not run with my buffer spring and H3....maybe it will. Only your field testing will confirm reliability and function. Anyways, reading the entire thread I posted above would be very helpful for you.
Thanks for this!;)
polymorpheous
09-05-10, 09:31
Ok...
Help me understand these springs...
I've looked at the Tubb CS flatwire
Tubb CS round
Wolff XP
I'm assuming I would want to find a "heavier" spring to slow things down.
Do these things have a weight similar to a pistol's recoil spring?
Why don't they make these things in stainless?
Also, all I could find on Sprinco's site were 1911 recoil springs.
Someone school me on springs please!:thank_you2:
Robb Jensen
09-05-10, 09:33
Dano is right.
There are two methods for controlling recoil, less moving mass or moving more mass slower.
For competition I've done both extremes. Full blown race gun and a pretty much stock M4. By full blown race gun I mean adjustable gas blocks combined with a low mass carrier (6oz) and very light buffers. These are good for the most part for competition but are much more sensitive to changes in ammo, weather, dirt/carbon and lube. Sometimes the guns are just running on the edge of reliability and if you say shoot them in urban prone all the sudden they quit working.
Obviously an almost bone stock M4 runs very reliably but has more recoil etc.
Now I'm using a very reliable not very race in the sense gun for 3gun.
My primary scoped 3gun rifle is set up like this:
16" BCM SS410 midlength
BCM M16 BCG
VLTOR A5 receiver extension(5oz buffer with a rifle length buffer spring) and Magpul ACS stock on it.
pinned VLTOR gas block
13" Troy/VTAC TRX FF tube (hoping they make a 15")
AAC M4-2000 51 tooth brake (modiifed)
Bobro 30mm scope mount with a Burris XTR 1-4x scope
http://img.photobucket.com/albums/v408/gotm4/BravoCoUSA%20and%20BCM%20album/BCM3gunrifle-1.jpg
I've modified the brake so that it has a port on the right side to neutralize any muzzle jump to the right and a ported it on the top to control muzzle lift. It shoots as soft as my old SJC Titan did on a 18" rifle gas barrel that I used to use before getting BCM as a 3gun sponsor. I've also used a long Surefire FA556 brake on this SS410 barrel as well as a Benny Hill Rolling Thunder. The AAC brake that I've modified that's on it now shoots softer and I have more control over the gun vs. both of the others.
My Limited division 3gun rifle (iron sighted gun) is set up this way:
16" BCM midlength chrome lined
14" Daniel Defense Lite Rail
BCM M16 BCG
Magpul ACS stock w/H buffer, BCM rec. ext. and BCM CAR spring
AAC Brakeout brake/FH combo
shaved FSB (fits under the rail)
Colt carry handle with NM hooded rear aperture
Daniel Defense rail mounted front sight with NM front sight post
http://img.photobucket.com/albums/v408/gotm4/BravoCoUSA%20and%20BCM%20album/BCMLTDrifle.jpg
Shoots very soft for a iron sighted gun.
3500 rounds through the SS410 gun and over 2500 rounds through the iron sighted gun. I have yet to have a single stoppage and I've run weak ammo and put the guns through some very odd positions. I'm still keeping up with Master and GrandMaster shooters shooting much more 'race' type guns and I'm only a B class shooter.
We took 3rd at Topton 3man 3gun this year, the very well known Noveske Shooting Team took 4th. I did most of the rifle shooting for our team (Team VA Arms).
http://www.toptonfga.org/IPSC/Results-2010/results_06-20/ZOMBIE.pdf
Also, all I could find on Sprinco's site were 1911 recoil springs.
http://www.sprinco.com/tactical.html
polymorpheous
09-05-10, 09:59
http://www.sprinco.com/tactical.html
Of course!
It's gotta be TACTICAL!:lol:
Thanks Rob!
polymorpheous
09-05-10, 10:04
GotM4,
I'm leaning towards the heavier/slower side.
Thanks.:)
Robb Jensen
09-05-10, 10:10
GotM4,
I'm leaning towards the heavier/slower side.
Thanks.:)
Good choice. The softest is the rifle length gas, rifle weight buffer with rifle length buffer spring. The closest you get back to that the better.
My 3gun rifle (the scoped one) shoots way softer using the VLTOR A5 rec. ext. 5oz A5 buffer with the rifle length buffer spring vs. the older BCM rec. ext. H buffer and CAR buffer spring. Eventually the Limited (iron sighted) rifle will have a VLTOR A5 rec. ext. and A5 buffer and rifle spring too.
I don't know anything about the SCAR, but here's a recoil impulse comparison I did yesterday...
http://www.youtube.com/watch?v=vWtRyZ9EeSk
I have been using a 9mm buffer in my middie for about 2 years now. I can honestly say I don't know if it really does anything as far as felt recoil. I don't know much about inertial mass affecting recoil, but i sometimes think the 9mm buffer smooths out the action, but at the back of the recoil cycle it almost seems to have more recoil.
That is because the 9mm buffer is really a big weight and does very little buffering. Use an H3 buffer, the sliding weights are what "buffer" and slow down the rebound.
It has sliding weights in it.
It has sliding weights in it.
But the ratio of body weight to "sliding weight" is lower than that of anything from the carbine to the H3 buffers. With most 9mm buffers, the body weighs more than the steel weights inside. Some 9mm buffers don't even allow any movement of the weights. Now, a 9mm (steel) buffer body with tungsten weights would have value for certain applications. But not with the steel weights.
So, what is that ratio? And what ratio would be ideal?
Magic_Salad0892
09-06-10, 01:28
Really? I was expecting them to run small but not that small. Whats the weakest ammo youve run on the above config?
55 gr .223 TAP will cycle the gun but sometimes wont lock back due to the Sprinco RED spring and H3 buffer. With the suppressor on, with my switchblock set to ''S'' it will lock back with a BLUE Sprinco spring. EVERY time.
I normally run M855 5.56 clone ammo, and 77 gr. 5.56 as noted above.
It cycles and locks back every time using that.
If you don't run .223 the RED should be fine IMO. (it was intended for 14.5'' carbines, but it'll run fine on a midlength I think, it runs fine on my KAC intermediate. Which is a little longer than midlength, I think it's like 11''.)
If you do go with the BLUE spring. H3 buffer should be okay on both setups.
Refer to rob_s though, as he'd have more experience.
I run mostly m193 but 223's do come into play on rare occasions so I the blue might be a better choice for me.
BTW, what 14.5 middy barrel with the 063" gas port are you running? DD or BCM?
Please forgive my hijack...
OK so now I'm interested in trying this on my rifle. I have a 16" carbine w/ H buffer. Should I go with an H2 or H3 buffer? Also should I try the sprinco red or blue? I am currently shooting M193 clone but do from time to time use the Wal-Nart federal 55gr and Rem green box 223.
There's no guaranteeing a similar result since yours is a car system and his is a 14.5 middy. Different gas systems and big difference in dwell time.
IMHO, you'd benefit more from a good comp than you would a buffer and spring change.
Suwannee Tim
09-07-10, 05:18
Why wouldn't I want to be able to make a faster follow up shot.
Why wouldn't I want to reduce my split time?
Why wouldn't I want to put 3 rounds downrange in the par time for 2 rounds?
Do you see where I'm going with this?
Sure I can see what you are trying to do. Bullseye competitors try to reduce the recoil impulse of 45 ACP and going to 9mm is not an option as it is not allowed by the rules.
Nevertheless I can't help but be amused by the idea of reducing the recoil of the 5.56.:D
Sure I can see what you are trying to do. Bullseye competitors try to reduce the recoil impulse of 45 ACP and going to 9mm is not an option as it is not allowed by the rules.
Nevertheless I can't help but be amused by the idea of reducing the recoil of the 5.56.:D
I'm not sure if you're getting the point or not. This is not about "reducing recoil" as much as reducing muzzle climb and therefore time between shots. Nobody is saying that 5.56 is knocking them over, or hurting their shoulder, or causing a flinch, or anything like that. Regardless of caliber, lowered felt recoil and decreases muzzle climb are good things with no downside provided they do not negatively affect reliability.
Suwannee Tim
09-07-10, 08:59
I get it, you are trying to shoot fast and accurate and you want the rifle to be as cooperative as possible. My perspective is the 30-06 to which I compare all other rifle cartridges. In my world, too much recoil means the rifle gives you a nosebleed or loosens fillings when you shoot it. I'm new to this AR shooting and I can't help but be amused by discussions like this. I do agree that there is no good that comes from recoil. I have heard folks brag about how they like it, I find that hard to believe. I enjoy the challenge of mastering difficult tasks, and shooting big rifles is one of them. If it was easy or enjoyable everyone would be good at it.
Col_Crocs
I have a BC on it now and it did wonders. I am just curious as to what effect a heavier buffer and or spring might have with a CAR system. I guess I just may have to purchase both the red and blue springs along with H2 and H3 buffers and see what will work and what will not and start a new thread to post the results.
It gets somewhat less amusing when somebody is shooting at you, and being able to drive the gun faster, regardless of caliber, might possibly, concievably be a worthwhile operational consideration.
There are times when simply telling somebody "Harden the f**k up!" while snickering at them is ivory-tower meathead BS. You don't get to tell that smaller person, for example, be they male or female, that they can handle their shit the same way as you just because 30-06 is your metric. Especially when we're talking about stuff that enhances well-applied fundamentals and does not exacerbate badly-applied ones.
Given the opportunity to either fight harder or fight smarter, I'll choose, and train people to choose, smarter every day of the week and twice on Sundays. If that fighting smarter includes selecting an equipment mod that helps compensate for likely but impossible to fully predict circumstances (unconventional position, fast movement over broken ground, the concussion felt as the enemy casts his vote in the outcome, loss of the use on a limb, etc.), the I'm less likely to be amused and more inclined to listen to technical merits as applied to a spectrum of useage.
There are worlds other than competition or tender shoulders or tree stands or fully-functioning physiology to consider.
I get it, you are trying to shoot fast and accurate and you want the rifle to be as cooperative as possible. My perspective is the 30-06 to which I compare all other rifle cartridges. In my world, too much recoil means the rifle gives you a nosebleed or loosens fillings when you shoot it. I'm new to this AR shooting and I can't help but be amused by discussions like this. I do agree that there is no good that comes from recoil. I have heard folks brag about how they like it, I find that hard to believe. I enjoy the challenge of mastering difficult tasks, and shooting big rifles is one of them. If it was easy or enjoyable everyone would be good at it.
You view the AR15 platform as just another shooting challenge. Most people in that arena are far more purpose-oriented. They tend to view it as a weapon system. The purpose of these rifles has virtually nothing to do with your 30-06.
TwoSqueeze
09-07-10, 11:02
It gets somewhat less amusing when somebody is shooting at you, and being able to drive the gun faster, regardless of caliber, might possibly, concievably be a worthwhile operational consideration.
There are times when simply telling somebody "Harden the f**k up!" while snickering at them is ivory-tower meathead BS. You don't get to tell that smaller person, for example, be they male or female, that they can handle their shit the same way as you just because 30-06 is your metric. Especially when we're talking about stuff that enhances well-applied fundamentals and does not exacerbate badly-applied ones.
Given the opportunity to either fight harder or fight smarter, I'll choose, and train people to choose, smarter every day of the week and twice on Sundays. If that fighting smarter includes selecting an equipment mod that helps compensate for likely but impossible to fully predict circumstances (unconventional position, fast movement over broken ground, the concussion felt as the enemy casts his vote in the outcome, loss of the use on a limb, etc.), the I'm less likely to be amused and more inclined to listen to technical merits as applied to a spectrum of useage.
There are worlds other than competition or tender shoulders or tree stands or fully-functioning physiology to consider.
Well put.:thank_you2: Perfectly articulates the way I feel about constant adaptation of gear, tactics and strategy. Wish I had the vocabulary, and patience for that matter, to come up with that.
-TS
Suwannee Tim
09-07-10, 11:59
There are times when simply telling somebody "Harden the f**k up!" while snickering at them is ivory-tower meathead BS. You don't get to tell that smaller person, for example, be they male or female, that they can handle their shit the same way as you just because 30-06 is your metric.
I never said that nor is that my attitude. I thought this was a friendly discussion. Guess not.
I never said that nor is that my attitude. I thought this was a friendly discussion. Guess not.
He wasn't trying to be rude. I believe he was referring to the common tuffman attitude that is pervasive that if you can't do what everyone else does then you aren't trying hard enough, which is not always the case as he is stating. Some people do need to just shoot more and this gets the planets aligned for them and some genuinely have to make compromises in equipment that will hopefully make up the difference in what they lack to perform as is expected while they get dialed or possibly always. I can shoot a FAL rifle faster and more accurately than an M4, this probably should not be the case... but the light weight and violent fast recoil of an M4 makes the sights jump all over the place for me. My splits are a joke. Shooting it more will probably fix this, but in the mean time a comp or brake or a longer gas system might help me "keep up" until I get dialed. Being a FAL guy and spending years working in Africa I laughed at the 556 & AR platform too, until I started shooting one. For its intended purpose the 556 works and the AR platform I now think is wonderful, but it is difficult for me to get fast accurate followup shots because it is so light and has a very unfamiliar recoil impulse.
If you're tuff enough to handle the bark of those 30-06 rounds then be tuff enough to have people on here bark at you a bit. Its all just tuff love:p
polymorpheous
09-07-10, 15:25
If you're tuff enough to handle the bark of those 30-06 rounds then be tuff enough to have people on here bark at you a bit.
Good stuff.
polymorpheous
09-07-10, 15:35
So can anyone school me on action springs?
I already decided on trying a "H2" buffer.
Also, I don't have a clue as to what the gas port size is.
But it handles all the underpowered plinking ammo just fine.
My buddy has a 14.5" LMT upper and the Tula ammo won't lock the bolt back on an empty mag.
We are thinking it is that particular lot of ammo.
But I'm raising my eyebrow at my upper now.
I'm wondering if it is overgassed?
It spits out casings at 4 0'clock... so maybe not...
As someone that has done a lot of gas port size to barrel length comparisons and owns the softest recoiling suppressed 10.5 on the planet (that I am aware of), let me add my two cents.
1. Training plays a big part in shooting fast and controlling your weapon.
2. Body position, balance, position of your hands and arms contribute greatly to the speed in which you can drive the weapon.
3. Heavier buffers and X power/CS springs do add a certain level of control, but not as much as the above two.
4. Ammo selection plays into this as well (soft vs hot).
With that said, most companies use gas ports on the large side. Mil-spec 14.5" M4's have a GP size of .063. Is this too much gas? Yes. Does it make the gun more reliable when the going gets tough (meaning dirt and grime build up)? Yes.
Middy uppers (especially ones that are 14.5" have to have larger GP's to make sure they run with under pressured ammo (like what the OP is using). If everyone shot M855, manufacturers could use smaller GP's. That's never going to happen though.
Compensator's. These work wonders for controlling muzzle rise/flip. Some of the best are the SF MB566K, KAC TTB, BattleComp, etc. There is a trade though. More flash signature, much higher noise levels (which is really annoying to me). So you have to ask yourself if those two issues are worth it to you? To me, no they are not, but then again, I do not compete in gun games. YMMV.
C4
Thomas M-4
09-07-10, 16:10
Grant have you tried the vltor A-5 buffer system on the ultimate sbr yet?
I never said that nor is that my attitude. I thought this was a friendly discussion. Guess not.
Guess again.
Terse is not automatically indicative of unfriendly, hostile, or indifferent. In regard to my own subculture, what I said wouldn't even register as a blip on the Mildly Unfriendly scale.
My metric for conversations with my peers is how long it takes to end up on the floor in some sort of mutual armbars, laughing and trying to brain each other with whatever heavy object is handy while still arguing the merits/flaws of Whatsis vs. Thingamajig, while the office wogs look on and shudder at how much they'd have to pay in dry cleaning to remove blood stains from the fronts of their shirts. It's invigorating.
So, given that, and given that your metric for recoil is 30-06, to paraphrase somebody else, we're all victims of our frame of reference.
Tallking springs, what's this "flat spring" I've heard bandied about elsewhere? Tubbs, is it? What's that supposed to do for the process? I'm not spun up on how the shape of a spring affects the way it operates vs. material and tempering process......
polymorpheous
09-07-10, 16:31
As someone that has done a lot of gas port size to barrel length comparisons and owns the softest recoiling suppressed 10.5 on the planet (that I am aware of), let me add my two cents.
1. Training plays a big part in shooting fast and controlling your weapon.
2. Body position, balance, position of your hands and arms contribute greatly to the speed in which you can drive the weapon.
3. Heavier buffers and X power/CS springs do add a certain level of control, but not as much as the above two.
4. Ammo selection plays into this as well (soft vs hot).
*snip*
C4
Thanks for chiming in Grant.
I'm gonna keep on training.
I haven't perceived anything wrong with my body mechanics.
No one's called me out on it either.
I wish they would if I'm doing something wrong.
Suwannee Tim
09-07-10, 17:16
Rough and tumble. OK, got it. Just don't tickle me. That 30-06 reference dates back almost 40 years to when I was 14 and got my first center fire rifle, an '03A1. I mostly rate recoil in multiples of '06, less often, fractions thereof. There are lots of better men than I who have not nearly my tolerance for recoil so I don't regard that as a metric of manhood or womanhood as the case may be. I do "get it" that while for me, the AR is a toy, for lots of folks it is a tool, two very different perspectives. As far as polite versus hostile, maybe I have let my local range etiquette affect me too much. There, Gateway Rifle and Pistol Club, when someone points a firearm at me or another member and I have a chat with them, they are as likely as not to complain to the Board that I was mean to them. At the request of the Board I am trying to learn to be nice. That request obviously does not apply to any of you.
polymorpheous
09-07-10, 17:27
Feels funny to say this, as I'm just a regular guy but...
Let's try and keep this thread on track please.
:nono:
3. Heavier buffers and X power/CS springs do add a certain level of control, but not as much as the above two.
Pursuing the spring aspect of this, in regard to my above about flat springs like the Tubbs.....
From their website: http://www.davidtubb.com/tcom_images/ar15_images/cs_flatwire.html
At installed height (bolt in battery) the load on the bolt is increased by about 10% compared to our CS round wire spring. This works more energy before the bolt unlocks and provides a flatter recoil impulse. This minimizes the effect of the spring returning the bolt to battery. The CS flat wire spring requires about 6% less force to fully compress than our CS round wire spring.
It's not just possible, but likely, that my mind is butchering the language, but I read that as saying that the flat CS spring somehow simultaneously applies both more and less force on the bolt. How's that work?
What's happening within the material that's different at rest than when in motion under impulse and supposedly produces a difference as to how that impulse if felt by the shooter?
Is that the intent, or is the intent strictly to affect how the action works, and how the impulse if felt is just a by-product of what's happpening internally?
Is it more/less effective based on a particular gas system length?
Is it something that can be explained to an infantry proto-human like me by talking to him like he's 4?
polymorpheous
09-07-10, 18:33
Interesting claims they are making.
I'd like to know more about it as well.
thopkins22
09-07-10, 19:53
I don't know if their claims are true...I'm not a metallurgist. But I'll ask one.;)
Just an FYI if you have time or care to study geometrical spring design.
http://www.mitcalc.com/doc/springs/help/en/springstxt.htm
Pursuing the spring aspect of this, in regard to my above about flat springs like the Tubbs.....
From their website: http://www.davidtubb.com/tcom_images/ar15_images/cs_flatwire.html
It's not just possible, but likely, that my mind is butchering the language, but I read that as saying that the flat CS spring somehow simultaneously applies both more and less force on the bolt. How's that work?
What's happening within the material that's different at rest than when in motion under impulse and supposedly produces a difference as to how that impulse if felt by the shooter?
Is that the intent, or is the intent strictly to affect how the action works, and how the impulse if felt is just a by-product of what's happpening internally?
Is it more/less effective based on a particular gas system length?
Is it something that can be explained to an infantry proto-human like me by talking to him like he's 4?
This is just a swag, but I think it has to do with the flat wire being thinner and the overall spring length being longer than a standard action spring. The CS flatwire spring definitely feels stronger than a regular action spring and it takes a little more ooomph to rack the charging handle. I think that is where the 10% increase in bolt face pressure comes from.
Now, if you notice they said it took 6% less pressure to compress completely. The spring shouldn't come anywhere near complete compression during a firing cycle, maybe more like 50%. Maybe the spring rate is different for a standard spring and the flatwire CS spring, so that the amount of force required to compress grows at a greater rate on a standard spring? I assume they were comparing the amount of force to compress each spring completely, which doesn't happen in the firing cycle.
Magic_Salad0892
09-08-10, 04:03
I run mostly m193 but 223's do come into play on rare occasions so I the blue might be a better choice for me.
BTW, what 14.5 middy barrel with the 063" gas port are you running? DD or BCM?
KAC SR-15 E3 that I had cut to 14.5''.
So neither. What I'm saying is pretty subjective, but I've shot it on friends carbines with traditional lengths. (Their upper, on my lower.)
I haven't had the gas port measured but it hasn't been touched.
I'm almost positive it's .063'' though.
Grant have you tried the vltor A-5 buffer system on the ultimate sbr yet?
I have not Sir.
C4
Pursuing the spring aspect of this, in regard to my above about flat springs like the Tubbs.....
From their website: http://www.davidtubb.com/tcom_images/ar15_images/cs_flatwire.html
It's not just possible, but likely, that my mind is butchering the language, but I read that as saying that the flat CS spring somehow simultaneously applies both more and less force on the bolt. How's that work?
What's happening within the material that's different at rest than when in motion under impulse and supposedly produces a difference as to how that impulse if felt by the shooter?
Is that the intent, or is the intent strictly to affect how the action works, and how the impulse if felt is just a by-product of what's happpening internally?
Is it more/less effective based on a particular gas system length?
Is it something that can be explained to an infantry proto-human like me by talking to him like he's 4?
Good questions my friend. I have used the Tubbs springs. What the flat design of the spring gives you is the ability to get more spring into your RE (as the coils, when compressed, take up the same amount of space as a standard spring).
With that said, every Tubbs spring I have used had to be cut down (meaning I had to cut one coil at a time to get the desired result). This by the way, is perfectly acceptable (and expected) by Tubbs.
I am not a Spring Engineer nor a NASA door gunner, but from what research I have done, I can tell you that standard SS buffer springs have only about 10% of their lives left when NEW.
Have you ever shot a NEW AR and had to change the spring out because of malfunctions? I have. The reason that this can happen is because the buffer spring (just sitting in the gun) is losing its tension. Since it had so little to lose to begin with, it is possible that it is done before the gun is ever fired.
CS springs typically have 100,000 + compressions in them. Keep in mind that there are different grades of CS. The cheap stuff will rust very easily. The higher end CS has the ability to resist rust like SS does.
I typically ONLY USE Tactical SpringCo's CS buffer spring (middy version which has a blue end). They are about the same length as a standard USGI buffer spring and a not extra power (just extra life which is what I am after).
http://www.gandrtactical.com/cgi-bin/commerce.cgi?preadd=action&key=25006
Hope this helps....
C4
militarymoron
09-08-10, 09:34
I am not a Spring Engineer nor a NASA door gunner, but from what research I have done, I can tell you that standard SS buffer springs have only about 10% of their lives left when NEW.
Have you ever shot a NEW AR and had to change the spring out because of malfunctions? I have. The reason that this can happen is because the buffer spring (just sitting in the gun) is losing its tension. Since it had so little to lose to begin with, it is possible that it is done before the gun is ever fired.
CS springs typically have 100,000 + compressions in them.
grant, do you think that the buffer springs you've had to replace could just have been manufactured underpowered to begin with? if they're NEW, and last only 10% of how long they're supposed to, maybe they just weren't made to the proper spring rate.
as i understand it, springs lose their tension through duty cycles, unless stretched or compressed past their elastic limit. a new unused buffer spring has a cycle of one, in a partially compressed state, just like a new magazine spring. magazine springs don't wear out from keeping mags loaded, so it doesn't make sense (to me) that a buffer spring would be any different. that's why i'm guessing that the buffer springs that need replacement when new just didn't meet spec to begin with.
grant, do you think that the buffer springs you've had to replace could just have been manufactured underpowered to begin with? if they're NEW, and last only 10% of how long they're supposed to, maybe they just weren't made to the proper spring rate.
Entirely possible, but have seen it more than once.
as i understand it, springs lose their tension through duty cycles, unless stretched or compressed past their elastic limit. a new unused buffer spring has a cycle of one, in a partially compressed state, just like a new magazine spring. magazine springs don't wear out from keeping mags loaded, so it doesn't make sense (to me) that a buffer spring would be any different. that's why i'm guessing that the buffer springs that need replacement when new just didn't meet spec to begin with.
SS springs take a set everytime they are used, where as CS takes only one set. Your buffer spring is under tension (compressed) as it sits in your gun. This is why springs typically have a round count and time frame for change.
As far as mag springs, I think they are extended to close to their full length. I have also had dead mag springs as well.
Is it a common thing? Nope.
In my eyes, I want to make the weapon as reliable as possible. Being human means that I don't always remember to do my PM's. So I only use CS springs in my gun (where I can) so that I basically don't have to ever replace them.
C4
militarymoron
09-08-10, 10:43
It's not just possible, but likely, that my mind is butchering the language, but I read that as saying that the flat CS spring somehow simultaneously applies both more and less force on the bolt. How's that work?
What's happening within the material that's different at rest than when in motion under impulse and supposedly produces a difference as to how that impulse if felt by the shooter?
Is that the intent, or is the intent strictly to affect how the action works, and how the impulse if felt is just a by-product of what's happpening internally?
Is it more/less effective based on a particular gas system length?
Is it something that can be explained to an infantry proto-human like me by talking to him like he's 4?
i believe that the purpose of the flatwire spring is just to increase the number of active coils for a given compression length. speaking with eric at vltor about the A5 buffer system, that was the intent of the A5 - to provide more consistency (and reliability) each time the spring is compressed. according to eric, every spring has manufacturing variances in each coil, and increasing the number of coils for a given length provides a better 'average' compression force than a spring of the same length with less coils. having a more consistent spring force translates to more consistent ejection, etc.
tubbs' reference to recoil impulse is probably based on having a 10% stronger spring - nothing to do with the shape or number of coils.
as for how "the flat CS spring somehow simultaneously applies both more and less force on the bolt", that's pretty easily explained - mtndawg was along the right track. the tubbs spring must have a different spring force constant than the round wire spring for it to have a longer uncompressed length, and provide a similar 'starting' force (if it were too great, the weapon would short stroke.)
here are just some example numbers i threw together to illustrate the physics - they are not to be taken as actual values:
Disclaimer: All spring lengths, weights, and spring constants appearing in the following example are fictitious. Any resemblance to real springs, living or dead, is purely coincidental. :)
tubbs flatwire spring
uncompressed (free) length: 12"
regular roundwire spring
uncompressed (free) length: 10"
both will be compressed to 6" in the buffer tube when installed, and compressed down to 3" when the bolt carrier is in the most rearward position.
using an arbitrary spring constant K of 10 (for ease of calculation - it's probably a lot less) for the roundwire spring, i calculated (using hooke's law F=kx, where x is the amount deflected from the free length):
spring force on bolt carrier when installed (compressed to 6"): F = 10 x (10"-6") = 40lbs
spring force on bolt carrier when compressed during firing: F = 10 x (10"-3") = 70lbs
now, given the 10% more load on bolt when installed and 6% less load on bolt when fully compressed numbers, i had to back-calculate the equivalent spring constant for the tubbs flatwire spring, and came up with 7.35
so, using 7.35 as K for the tubbs flatwire spring, i get:
spring force on bolt carrier when installed (compressed to 6"): F = 7.35 x (12"-6") = 44lbs, which is 10% greater than the roundwire spring.
spring force on bolt carrier when compressed during firing: F = 7.35 x (12"-3") = 66.15lbs, which is about 6% less than the roundwire spring.
so, that's how the tubbs can exert more force on the bolt carrier when installed, but less when compressed fully.
thopkins22
09-08-10, 11:06
here are just some example numbers i threw together to illustrate the physics - they are not to be taken as actual values:
tubbs flatwire spring
uncompressed (free) length: 12"
regular roundwire spring
uncompressed (free) length: 10"
both will be compressed to 6" in the buffer tube when installed, and compressed down to 3" when the bolt carrier is in the most rearward position.
using an arbitrary spring constant K of 10 (for ease of calculation - it's probably a lot less) for the roundwire spring, i calculated (using hooke's law F=kx, where x is the amount deflected from the free length):
spring force on bolt carrier when installed (compressed to 6"): F = 10 x (10"-6") = 40lbs
spring force on bolt carrier when compressed during firing: F = 10 x (10"-3") = 70lbs
now, given the 10% more load on bolt when installed and 6% less load on bolt when fully compressed numbers, i had to back-calculate the equivalent spring constant for the tubbs flatwire spring, and came up with 7.35
so, using 7.35 as K for the tubbs flatwire spring, i get:
spring force on bolt carrier when installed (compressed to 6"): F = 7.35 x (12"-6") = 44lbs, which is 10% greater than the roundwire spring.
spring force on bolt carrier when compressed during firing: F = 7.35 x (12"-3") = 66.15lbs, which is about 6% less than the roundwire spring.
so, that's how the tubbs can exert more force on the bolt carrier when installed, but less when compressed fully.
Pretty much exactly how my professor explained it to me this morning.
Robb Jensen
09-08-10, 13:16
Weighed some reciprocating mass today in three rifles:
FN SCAR: BCG, CH and recoil rod/spring assy 1lb 6.1oz
DDM4: M16 BCG, H buffer and spring 1lb 1oz
Bushmaster ACR: BCG w/recoil spring assy 1lb 2.8oz
militarymoron
09-08-10, 13:24
FN SCAR: BCG, CH and recoil rod/spring assy 1lb 6.1oz
the SCAR recoil rod doesn't reciprocate - it's fixed at the rear end.
Hope this helps....
It does...but then MM came along and did MATH all over me. :suicide:
I think I need to lay down.
Thomas M-4
09-08-10, 13:59
Is 7.35 K the correct value for the tubbs spring?
militarymoron
09-08-10, 14:11
Is 7.35 K the correct value for the tubbs spring?
no. see the words in bold.
Thomas M-4
09-08-10, 14:29
no. see the words in bold.
Ok roger that.
polymorpheous
09-08-10, 15:36
Great information MM!
Thanks for that!:cool:
Thanks militarymoron, I was hoping I wouldn't have to dig out an old physics textbook and now I definitely don't. :D
Robb Jensen
09-08-10, 16:21
the SCAR recoil rod doesn't reciprocate - it's fixed at the rear end.
True and it weighs next to nothing.
i believe that the purpose of the flatwire spring is just to increase the number of active coils for a given compression length. speaking with eric at vltor about the A5 buffer system, that was the intent of the A5 - to provide more consistency (and reliability) each time the spring is compressed. according to eric, every spring has manufacturing variances in each coil, and increasing the number of coils for a given length provides a better 'average' compression force than a spring of the same length with less coils. having a more consistent spring force translates to more consistent ejection, etc.
tubbs' reference to recoil impulse is probably based on having a 10% stronger spring - nothing to do with the shape or number of coils.
as for how "the flat CS spring somehow simultaneously applies both more and less force on the bolt", that's pretty easily explained - mtndawg was along the right track. the tubbs spring must have a different spring force constant than the round wire spring for it to have a longer uncompressed length, and provide a similar 'starting' force (if it were too great, the weapon would short stroke.)
here are just some example numbers i threw together to illustrate the physics - they are not to be taken as actual values:
tubbs flatwire spring
uncompressed (free) length: 12"
regular roundwire spring
uncompressed (free) length: 10"
both will be compressed to 6" in the buffer tube when installed, and compressed down to 3" when the bolt carrier is in the most rearward position.
using an arbitrary spring constant K of 10 (for ease of calculation - it's probably a lot less) for the roundwire spring, i calculated (using hooke's law F=kx, where x is the amount deflected from the free length):
spring force on bolt carrier when installed (compressed to 6"): F = 10 x (10"-6") = 40lbs
spring force on bolt carrier when compressed during firing: F = 10 x (10"-3") = 70lbs
now, given the 10% more load on bolt when installed and 6% less load on bolt when fully compressed numbers, i had to back-calculate the equivalent spring constant for the tubbs flatwire spring, and came up with 7.35
so, using 7.35 as K for the tubbs flatwire spring, i get:
spring force on bolt carrier when installed (compressed to 6"): F = 7.35 x (12"-6") = 44lbs, which is 10% greater than the roundwire spring.
spring force on bolt carrier when compressed during firing: F = 7.35 x (12"-3") = 66.15lbs, which is about 6% less than the roundwire spring.
so, that's how the tubbs can exert more force on the bolt carrier when installed, but less when compressed fully.
did u measure the wire diameter from the original spring and width and thickness from the cs spring .... from what i remember form machine element design course they come in to play for the computation of K.
aside from that great job :) i love being a MECH eng.
militarymoron
09-08-10, 22:07
did u measure the wire diameter from the original spring and width and thickness from the cs spring .... from what i remember form machine element design course they come in to play for the computation of K.
aside from that great job :) i love being a MECH eng.
i didn't make any measurements - all numbers used are arbitrary for use as an example. the spring constant could be anything - i picked '10' because it's easier to illustrate the math with. it could be 2, 5, 7.5 etc. same thing with the free length, installed length and compressed length - those are not actual or measured numbers.
militarymoron
09-08-10, 22:07
True and it weighs next to nothing.
touche. :)
Weighed some reciprocating mass today in three rifles:
FN SCAR: BCG, CH and recoil rod/spring assy 1lb 6.1oz
DDM4: M16 BCG, H buffer and spring 1lb 1oz
Bushmaster ACR: BCG w/recoil spring assy 1lb 2.8oz
I think we need to examine them not just as complete assemblies but as components. For example, as discussed, almost all of the SCAR's 22oz is one big chunk that moves together, while the AR's 17oz isn't exactly the same - especially when the function of the buffer weights is considered.
Also, the BCG of the AR moves closer to the point that the weapon pivots from (the shoulder) than the SCAR. So I think stance is less important with the AR in terms of keeping the weapon on target. I'm not saying that it's not important with an AR or that you shouldn't concentrate on your stance, just that the SCAR tends to get away from you easier if you don't have a good stance.
Robb Jensen
09-09-10, 07:46
I think we need to examine them not just as complete assemblies but as components. For example, as discussed, almost all of the SCAR's 22oz is one big chunk that moves together, while the AR's 17oz isn't exactly the same - especially when the function of the buffer weights is considered.
Also, the BCG of the AR moves closer to the point that the weapon pivots from (the shoulder) than the SCAR. So I think stance is less important with the AR in terms of keeping the weapon on target. I'm not saying that it's not important with an AR or that you shouldn't concentrate on your stance, just that the SCAR tends to get away from you easier if you don't have a good stance.
I agree I think the reciprocating weight further from your shoulder causes the more muzzle lift and that weird wavy recoil when fired quickly. I think it's much harder to control with stance. Probably why the civilian SCARs come with PWS556s to help control some of the muzzle lift. THe ACR has the same weird rhythmic recoil and muzzle lift too.
I have a few friends who are sponsored by FNH and are shooting SCARs in 3gun. One guy is making a bolt on rail extension to be able to get a more aggressive stance with it.
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