View Full Version : Educate me on 10.5" and cans....
....this is a way down the road project as I just don't have the bones to throw at it all right now. I'm starting off with a dedicated Sun Devil that I'm gonna get for a song & will work the pw/stamp here in the next 2-3 I hope.
I'm open for suggestions from there. My biggest concern is gas vs. piston. Buy the upper complete ready to go or build??
I also tend to like the heavier bullets....7 / 8 twist ok or does everyone just shoot 55ball and go with a 1/9.
Also clueless on cans. I have a TAC67 on my anschutz but figured there were 2-3 favorites for this set up. I also like the idea of taking apart the can to clean but guessing all high pressure ones are sealed?? I am not a brass flinger & it pains me to get a barrel real hot. Strictly a fun gun.
Thanks!!
The best bang for the buck in a can for a 10.5 is the M4-2000. It's under a thousand dollars.
A can on an SBR is still too loud for me to shoot without ear pro. Some people aren't bothered by it, but my ears ring... especially the ear by the ejection port.
I don't run my can on anything under 14.5" since for recreational shooting, it defeats the purpose. Shooting a silencer with ear pro on is just putting wear on your can.
5.56 rifle cans are somewhat maintenance free. I just clean my mount and what I can get in the blast chamber.
For 10.5, an LMT is the way to go. If you're mounting a can, you might as well get every bit of 1/7 twist to safely stabilize the bullet as it goes through the baffles. I had a guy shoot a mag full of M855 through my M4-1000. It was mounted on a 1/9 twist barrel. I was a little concerned since ss109 is a fairly long bullet, but it did fine.
The best bang for the buck in a can for a 10.5 is the M4-2000. It's under a thousand dollars.
A can on an SBR is still too loud for me to shoot without ear pro. Some people aren't bothered by it, but my ears ring... especially the ear by the ejection port.
I don't run my can on anything under 14.5" since for recreational shooting, it defeats the purpose. Shooting a silencer with ear pro on is just putting wear on your can.
Thanks, I am going to consider a longer bbl.....my ears ring all the time from my younger days. LOTS of doves and whitewings & paying the price. I always wear plugs. How loud is a 14.5" and how much does the can come into play before I can forget the plugs??
This was helpful.... :cool:
I can shoot the 14.5 without plugs. It really depends on lots of factors. If you're next to a wall or something, it's louder, etc. Some days it seems louder than others. I'd still get the SBR. It doesn't hurt to put mounts on multiple guns.
tweakmeister
03-31-09, 18:57
I tried to read a lot on this and have surmised the following:
55-75gr "okay" on 1/7 twist 10.5" barrels (LMT, etc.) with good ammo. NO wolf (too much risk of getting a bad round) that doesn't stabilize.
However, I would generally count on a can getting a baffle strike at some point, regardless of what ammo you use. No ammo is ever 100% perfect, as I've seen just about every brand have a bad lot and someone report a bafflestrike. This is where the manufacturer becomes important, as the good ones will help you replace it at low cost. Note also, if you blow through the can's tube, you'll be paying another $200 tax, as the ATF won't let the manufacturer create another can with the same #.
Another thing to consider is the shorter you go the more damage it will do to your can. Well "damage" may not be the right word but your can will have to be rebuilt much sooner. I talked to Kevin at AAC and he said when I was running my M4-1000 on a 10.5 barrel that it would have to be sent in to be rebuilt after 5k rounds but if I ran it on a 14.5 it would last up to 3 times longer. So I compromised and got a 12.5 Denny's Operator barrel. LMT makes a 12 inch piston upper also which if I was starting from scratch is probably the route I would go.
tweakmeister
04-01-09, 11:37
note the LMT 12" piston rod won't clear the AAC QD flashhider, though it's debatable if you'd ever really need to pull the rod for cleaning (maybe 5-10k rounds).
edit...apparently you can if you remove the barrel.
I tried to read a lot on this and have surmised the following:
55-75gr "okay" on 1/7 twist 10.5" barrels (LMT, etc.) with good ammo. NO wolf (too much risk of getting a bad round) that doesn't stabilize.
However, I would generally count on a can getting a baffle strike at some point, regardless of what ammo you use. No ammo is ever 100% perfect, as I've seen just about every brand have a bad lot and someone report a bafflestrike. This is where the manufacturer becomes important, as the good ones will help you replace it at low cost. Note also, if you blow through the can's tube, you'll be paying another $200 tax, as the ATF won't let the manufacturer create another can with the same #.
I personally can't bring myself to shoot a bullet longer than 62 grain thru my can, stan. I'm sure people do it, but I had a mild baffle strike with 55 grain bullets. It's still a mystery. I can nail it down to a 20 round window. But the can is fine and totally functional. There's just a couple of knicks out of the baffles and the end cap is barely noticeable.
I know a goon who shoots wolf through his can all the time. I doubt you have any more of a risk of a baffle strike with wolf than any other ammo. His blast chamber is kinda nasty and green though.
Depending on how much silenced shooting you do, you may never get a strike. There's no point in worrying about it. I got mine at about 1300 rounds, and I'm a 1500 rounds through my can with no further incidents.
note the LMT 12" piston rod won't clear the AAC QD flashhider, though it's debatable if you'd ever really need to pull the rod for cleaning (maybe 5-10k rounds).
Use red loctite on the flashider vs rocksett too maybe.
Hmm... I didn't know the rod wouldn't clear. You should use the rocksett and not loctite. They aren't that hard to take off even when rocksetted. After 5k rounds I'd probably want to take it off to clean the crown anyway.
I personally can't bring myself to shoot a bullet longer than 62 grain thru my can, stan. I'm sure people do it, but I had a mild baffle strike with 55 grain bullets. It's still a mystery. I can nail it down to a 20 round window. But the can is fine and totally functional. There's just a couple of knicks out of the baffles and the end cap is barely noticeable.
I would really prefer to run 62-75gr bullets....This baffle strike has raised some concerns.
I noticed pof has an 11.5" which looks cool.
Also, on these uppers when they come in....do you simply remove the flash hider and screw on the 1/2x28 can?? I don't think I want to mess with the quick connects as it will be dedicated.
tweakmeister
04-01-09, 21:44
Assuming it's a decent barrel, yes, you just screw it on.
I don't think I want to mess with the quick connects as it will be dedicated.
Fast attach is really the ONLY way to go. Before I actually owned a silencer, I though I'd be fine with a thread on can. Now that I've spent some time in the silencer realm, there's NO WAY I could say a thread on can would be the better choice for a auto loading gun.
glockshooter
04-02-09, 18:28
I also want to point out that most baffle strikes come from a can that has come loose while shooting. I have a YHM phantom, that I bought mainly because of the $260 dealer demo price I got it for. After shooting it and others, I have come to the conclusion that although it is heavier and the mount is ugly, it is probably the least likely can out there to have a baffle strike. You can have it only a couple of threads on and it will be correctly lined up. I think AAC is great stuff, and I would like to have one but I have talked to several people including Robb, that have had theirs shoot loose. When it comes to ammo problems it doesnt matter what can you have, but I believe most baffle strikes/ blown up can are alignment issues.
Matt
The best bang for the buck in a can for a 10.5 is the M4-2000. It's under a thousand dollars.
A can on an SBR is still too loud for me to shoot without ear pro. Some people aren't bothered by it, but my ears ring... especially the ear by the ejection port.
I don't run my can on anything under 14.5" since for recreational shooting, it defeats the purpose. Shooting a silencer with ear pro on is just putting wear on your can.
5.56 rifle cans are somewhat maintenance free. I just clean my mount and what I can get in the blast chamber.
For 10.5, an LMT is the way to go. If you're mounting a can, you might as well get every bit of 1/7 twist to safely stabilize the bullet as it goes through the baffles. I had a guy shoot a mag full of M855 through my M4-1000. It was mounted on a 1/9 twist barrel. I was a little concerned since ss109 is a fairly long bullet, but it did fine.
1/7 will actually cause MORE stability issues than 1/9 with the SS109 projectile. 1/9 was the original spec for that projectile and at 24-500fps and faster, provides a GSTAB of 1.28 or greater IIRC.
I recently had the opportunity to shoot a 10.5" AR with a Gemtech M4-02.
This combination is definitely not the quietest way to suppress an AR, but then again, the AR is not really worth suppressing.
The problem is the sonic crack from the bullet is pretty loud. Anyone who has worked "the pits" at a high power match can attest to that.
If you load up subsonic .223 loads, you now have a 70 gr, .22 cal bullet moving at .22 long rifle handgun speeds. You're better off with a 10/22.
So, you can have a quiet toy with useless balistics, or you can have a less loud, but uesful gun.
I've chosen the "less loud" route.
The Gemtech on the 10.5" results in a gun that is shorter than an M4 with a standard flash suppressor. Its much quieter, and is a lot of fun to shoot.
Re the wear and tear on the can. Gemtech will repair or replace the can forever. So no biggie.
I liked it so much I bought a LMT 10.5" upper and an M4-02. Still waiting on the paperwork for the M4-02
Don
p.s. if you want something quiet and useful, you need to go with something with a larger diameter like a 9mm or a .45. It would be great if someone worked up some 400 grain .458 Socom or .500 beowulf subsonic loads. The matching suppressor, if built to only survive subsonic pressures, could be made fairly light and small. That would be an interesting combination.
I recently had the opportunity to shoot a 10.5" AR with a Gemtech M4-02.
This combination is definitely not the quietest way to suppress an AR, but then again, the AR is not really worth suppressing.
That's your opinion. Thousands of use disagree. The AR is the ONLY gun I supress.
The problem is the sonic crack from the bullet is pretty loud. Anyone who has worked "the pits" at a high power match can attest to that.
The problem is MORE than simpley the sonic crack. A short barrel with silencer gives of very loud port noise. This isn't noticeable to bystanders, but it's loud in the shooter's position.
If you load up subsonic .223 loads, you now have a 70 gr, .22 cal bullet moving at .22 long rifle handgun speeds. You're better off with a 10/22.
A jacketed bullet can't really be compared to a rimfire projectile. People make this link all the time, and it's not valid. But I agree that subsonic AR ammo is silly nonsense.
The Gemtech on the 10.5" results in a gun that is shorter than an M4 with a standard flash suppressor. Its much quieter, and is a lot of fun to shoot.
Re the wear and tear on the can. Gemtech will repair or replace the can forever. So no biggie.
Every decent silencer maker will do this. Gemtec's cans are just not as robust as some of the others. If the can is beyond repair we all have to pay for a new tranfer... regardless of make.
p.s. if you want something quiet and useful, you need to go with something with a larger diameter like a 9mm or a .45.
This is completely false. Where did you get this idea from? .45 is one of the HARDEST calibers to silence. The larger the bore the harder it is to silence and still keep the diameter of the can reasonably small. This is why many of the .45 and some 9mm cans are fired "wet".
I dont know what the hell I was thinking when I said the .223 was not worth suppressing. I really meant to say that its not worth building up subsonic loads for the .223.
From there I should have said that if you need QUIET. You are better off with a 9mm. The point in my head, that I failed to make, was that a subsonic .223 is going to be quiet, but not terribly effective. A subsonic 147 grain 9mm is going to be (nearly) equally quiet, but pack much more of a punch.
Re the .45 being difficult to suppress. I have only shot a suppressed .45 once. It was an HK USP (or was that UMP), either way the conversion sub gun. It was very quiet, quiet enough so the loudest sound was the plate ringing and the action cycling.
I uncerstand that the large hole makes suppressing more difficult, but with subsonic ammo, its still pretty quiet, and with a 200+ grain bullet, it can be effective downrange.
Re longevity - my experience is admittedly limited to semi-auto use. So cans effectively last forever.
I didnt mean to single out Gemtech as better than other companies. My point was merely that if you shoot one out, they will fix it.
Don
p.s. thanks for keeping me in line. It was late, I couldnt sleep. ; -)
For 10.5, an LMT is the way to go. If you're mounting a can, you might as well get every bit of 1/7 twist to safely stabilize the bullet as it goes through the baffles. I had a guy shoot a mag full of M855 through my M4-1000. It was mounted on a 1/9 twist barrel. I was a little concerned since ss109 is a fairly long bullet, but it did fine.
1/9 is the most compatible twist for M855.
1/9 is the most compatible twist for M855.
Cool. I'm still nutty about sending longer bullets thru my can.
Re the wear and tear on the can. Gemtech will repair or replace the can forever. So no biggie.
Most of the big names will also do this but you now will pay a $200 gem-tax so to me it is a "biggie" to have to send my can in to be serviced.
Re longevity - my experience is admittedly limited to semi-auto use. So cans effectively last forever.
Forever huh? So Kevin from AAC and Trey Knight were wrong when they both told me even on a semi-auto the can will need to be serviced after 5k rounds give or take on a 10.5?
I guess if you shoot 20 rounds every other months very very slowly then yeah it may last forever. Some people run their semi's pretty hard though.
Cool. I'm still nutty about sending longer bullets thru my can.
Same here. I had several endcap strikes shooting factory fresh brand new IMI m855 through a Colt 6721 upper with an SWR Specwar-2 attached. Thankfully the can was not destroyed and after a short trip back to SWR, Joe confirmed that it was in no way adversely affected. But after that experience I stopped shooting heavy bullets through a suppressor on a 1:9 twist barrel. Could it have been the ammo? Sure and my experience is purely anecdotal and non-scientific.
Josh,
this time I did type it correctly. They effectively last forever because the manufacturer will service them at no charge. Thats what I meant, and thats what is plainly written in my post.
I wasnt trying to say that they do last forever. If I was, I would not have used the word "effectively".
Re Gemtax - what are you refering to?? Theres no tax for the original manufacturer to replace the internals of its own product. Perhaps you should do a bit more reading. Besides, the Gemtax is a misnomer (putting on nomex underware), it should be called the AACGemtax.
Don
Re Gemtax - what are you refering to?? Theres no tax for the original manufacturer to replace the internals of its own product. Perhaps you should do a bit more reading. Besides, the Gemtax is a misnomer (putting on nomex underware), it should be called the AACGemtax.
If the manuf can't repair or practically replace the internals, you get stuck with a new can and a new tax stamp.
Gemtec might be able to disasemble their cans, but I don't think AAC (for example) is able to do this. Their cores are welded, then welded into the tube. It's great for durability, but it's not easily repaired if you get a struck baffle.
So I guess its better called an AACTax then. Hmm.
Don
p.s. I'm just stirring up the shit. I understand that the term came from Gemtech "blowing the whistle" on AAC's "upgrade" process that actually replaced the entire suppressor.
Well I can see that your knowledge far exceeds mine so I will avoid trying to figure out what you are trying to say in the future and just "do more reading" about how awesome Gemtech is....
Longer bullets are generally more likely to have baffle strikes that shorter.
TRACER bullets are much more likely to have baffle strikes than FMJ or OTM's.
Cans on short 5.56mm guns errode the baffles much more quickly than longer guns, even on semi-auto. If you are a non governmental suppressor user, you want to use a mount that has a intial blast baffle built into it, as depending on construction this can double or triple the life of your can.
I've blown out several cans in my day :D
Out at the range in Afghan, we took a bunch of pics one day.
http://img.photobucket.com/albums/v193/EvilKev/Afghan%20Take%20II/Step6.jpg
http://img.photobucket.com/albums/v193/EvilKev/Afghan%20Take%20II/Step7.jpg
http://img.photobucket.com/albums/v193/EvilKev/Afghan%20Take%20II/Step10.jpg
I've got some pics of KAC, Gemtech, OpsInc, Br-Tuote, Brugger and Thommett etc. cans that I or co-workers have blown.
The KAC we damaged at work, shooting a NT3 on a Stoner LMG Short Barrel, a M856 tracer did a U turn down the pipe and an unpleasant end cap strike occured.
Worst suppressor issue I have seen was a B&T SOPS M4 can that literally detonated and several onlookers took shrapnel off the can body . B&T admitted shipping a defective bunch of cans later, but one of the guys wife's who was on looking still had a 15 stick cut in her face...
Please tell me where I said Gemtech was awesome. I cant seem to find that.
Dig that up for me and let me know.
So in case you need it spelled out agaon. My point was that the M4-02 is small, light, and cheap. It is nowhere near the most effective can you can buy for an AR. But represents a reasonable compromise based on my requirements, between size, cost and effectiveness.
I do believe that continuously welded AAC cans are generally tougher and quieter. The downside (and there is always a compromise in any engineering decision) is cost and the added difficulty in rebuilding an AAC.
The closest equivalent AAC can is the Ranger 2. Similar cost, similar weight, and most likely similar performance. (speculation, I havent heard the Ranger 2, but even AAC says that it is nowhere near as quiet as their larger .223 cans) If I was a military guy who needed the toughest suppressor possible it would not be a non-welded Gemtech.
But as a civilian, the risks my suppressors face are not thermal destruction caused by the need to shoot 500 rounds during a 15 minute firefight. Rather the risks to my cans are:
1) baffle strike
2) corrosion
With respect to both of those risks, I am better served by the less stoutly built, but more easily repairable Gemtech.
The fact that I was able to pick up a dealer demo for $150 off MSRP makes it a no-brainer.
Don
How is that. Logical?
But as a civilian, the risks my suppressors face are not thermal destruction caused by the need to shoot 500 rounds during a 15 minute firefight. Rather the risks to my cans are:
1) baffle strike
2) corrosion
You really can't live in fear of a baffle strike. It's like worrying about a car accident.
And as far as corrosion, you're best bet is inconel baffles. I think even the Ranger can has inconel. I'm making that assumption because AAC has said that the Ranger baffle stack is the same as the M4-1000, and it has inconel baffels.
But you got a good price on your can. Nothing says you won't want another one after you get this one. I know I bought a second can after my first.
I dont worry about baffle strikes. But its nice to know that if I have one, the manufacturer can open it up and replace the baffles without me having to spring for another stamp.
This M402 will most likely spend its life locktited to the end of my 10.5" upper. So its nice to know that if I have corrosion problems with the inner tube, it can be removed from the outer tube without another stamp.
Of course I'll store it tip down and shoot some boeshield in it when possible. But if corrosion happens I should be covered.
God only knows if my logic will pan out. But it makes sense at this point.
Again, I realize this could be completely avoided by purchasing a can made from inconnel and stainless, but I'm not going to be buyint ghat for less than 400
Don
I dont worry about baffle strikes. But its nice to know that if I have one, the manufacturer can open it up and replace the baffles without me having to spring for another stamp.
Silencers of this method of construction are the most likely to have a baffle strike.
Silencers of this method of construction are the most likely to have a baffle strike.
Roger that -- the best way to get a concentric suppressor alignment is to EDM cut after the welding of the baffles takes place.
Which makes it impossible to replace the internals.
Interesting, kindof a catch 22.
I get what you mean though. I think. Are you saying that after welding the baffles they essentially re-run some kind of tool down the bore again to make sure that everything is alligned?
Don
Interesting, kindof a catch 22.
I get what you mean though. I think. Are you saying that after welding the baffles they essentially re-run some kind of tool down the bore again to make sure that everything is alligned?
Don
They use a wire EDM machine. The wire "cuts" the bore of the silencer. The wire is electrically charged and actually removes material like arc welding in reverse.
Keep'em coming gang..thanks!!
In regards to the quick attach?? I was looking at the aac site and am a little confused and the accessories link is out?? Anyway, I'm assuming all the uppers will come threaded 1/2x28 with a flah hider attached. It appears the m4's come with the fast attach....Is putting the bbl adaptor a do it yourself job??
Just remove the installed flash hider & I assume the bbl has an attachement of sorts that mates with the can??
Another thing to consider is the shorter you go the more damage it will do to your can. ~ So I compromised and got a 12.5 Denny's Operator barrel.
I was going to recommend a Denny's Operator 12.5 as well.
Does Denny's have a web site??
Does Denny's have a web site??
PMing you.
What parts generally suffer damage from a short bbl?
Is it the first baffle?
If so, (and I fully accept that in every other way a Gemtech is inferior to an AAC), wouldnt the "non-welded" aspect of the gemtech facilitate warranty repair after it is "damaged".
Don
p.s. I'm not pushing Gemtech. Its just what I'm familiar with. My point, removing any brand affiliation, is essentially that although a non-welded can is probably inferior to a welded can as far as ultimate durability, a welded can is more deifficult to repair without destroying the outer tube.
If thats true, and considering that all the mfgs provide a pretty much no questions asked warranty, wouldnt a non welded can give the average civilian better service.
I fully understand that in a military or even "your life depends on emptying 10 mags" SHTF scenario, a welded can will last longer. In that situation, you will just throw your destroyed can away, so the ultimate reliability of the welded can is a benefit.
But for us mere mortals, I think the ability to pack it up and ship it back for a free rebuild might be a plus.
Educate me. Please spare the sarcasm. If I'm off, then give me a logical reason why. This is as much a question as a statement.
It's going to be a LONG time before you see any more 12.5 Denny Operator barrels.....
QuietShootr
04-12-09, 21:48
What parts generally suffer damage from a short bbl?
Is it the first baffle?
If so, (and I fully accept that in every other way a Gemtech is inferior to an AAC),
Mm. I don't think so. But I'm not going to open that can of worms here.
I dont necessarily believe that. But I wanted to remove that from the discussion. Since i was accused of being a "gemtech fan".
The first baffle will take the brunt of the unburned powder and be etched and well as the heat and flame will errode it - sooner than the subsequent baffles.
Hence why some sell their suppressors with a "sacrificial baffle" mount -- Surefire's Muzzle is an example of this - the small ID at the muzzle end restricts the flame cutting and powder errosion that would be hitting the firt baffle.
With this type of mount you really don't want to use it (tactically at least) w/o the suppressor.
IIRC GemTech can no longer rebuild suppressors for the public, but I may be wrong.
Essentially, if you're running a 10.5" bbl in 1/9 twist with a can on it, it's best to stick with 55 gr. bullets. Longer boat tail bullets, which also happen to be heavier, tend to yaw as they exit the muzzle. Hence the propensity to have baffle or end cap strikes. I have various cans in both QD & thread mount; one of which is an M4-02. If you have one, don't sweat it & just enjoy!
dancetiger
04-14-09, 19:22
I have a POF 9" upper, 1 in 7" twist with an AAC M4-2000 07. I have shot Hornady 5.56 75gr TAP ammo through it with no problems. I also have shot 62gr and 55gr ammo with no problems. The Hornady 556 TAP was very accurate too.
I have a POF 9" upper, 1 in 7" twist with an AAC M4-2000 07. I have shot Hornady 5.56 75gr TAP ammo through it with no problems. I also have shot 62gr and 55gr ammo with no problems. The Hornady 556 TAP was very accurate too.
Yeah. There's a myth out there that the longer bullets have to be fired from a barrel longer than 10.5 to be stable. In other words, they need to be going fast.
I've never subscribed to this rubbish.
I am the author of an iPhone app called BulletTwist. It computes a formula devised by Mr. Miller that is more advanced than Greenhill. This feature is also in my other app, BulletFlight -- a ballistic computer I did for KAC.
The Hornady 75 grain AMAX is 1.070 inches long. A Sierra 77 is .985. A Barnes TSX 70 is 1.030.
Here is a scenario:
Hornady 75, 2400fps, 1:9 twist, 0 degrees F, 30.42 InHG air pressure - stability factor is just 0.90. NOGO.
Change temp to 90 degrees F, and 29.92 pressure, and stability is 1.1. That is marginal, but it would look normal to a shooter.
A shooter would post on an interweb forum "Works fine, you can shoot it." They would be giving bad advice because it won't work for someone after the temp drops.
I like to check stability at 0 degrees F and a higher than normal atmospheric pressure to determine worst-case.
Now back to 0 degrees F, 1:8 twist is 1.16 stability. Marginal. Not good enough.
1:7 twist, stability goes to 1.51. Excellent.
If you shoot AMAX 75 grain bullets at around 2400fps, you want a 1:7 twist, period. TAP 75 NATO ammo is
perhaps the single best load for defense so that is why I want 1:7.
If you shoot the Sierra 77, then 1:8 is fine If you shoot Sierra 69, you can do 1:9.
At 2850 fps the Amax 75 is now ok in 1:8 but still not 1:9 unless it is warm out (around 70+).
If you will ever do subsonic, then I would have to recalculate with about 800fps.
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