Suppressors suppressed 7.5" AR...

codlinjr

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Full Member
Minuteman
Nov 5, 2005
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SE FL
thinking of putting one together in the near future, just for shits and gigs really.

anyone here have one that could post picts/specs and/or input about how you like or dislike it?
 
Re: suppressed 7.5" AR...

My Sergeant has one and it's ok to shoot with the can on. He put a muzzle brake on it to help keep erosion at bay on the first baffle. It sucks shooting the gun with the can off.

Most companies dont warranty the can if it mounted on anything shorter then 10.5

Lose muzzle velocity as well. If you have to have a 7.5" I would run the 50 grain Barnes TSX. Very good ballistics out of short barrels.
 
Re: suppressed 7.5" AR...

With barrels under 10" it really becomes more a matter of "when" you have end cap or baffle strikes instead of "if" you have them. Bullet stabilization is much more of an issue on those really short barrels.

Then as already mentioned baffle core erosion is another consideration. Suppressors are "wear" parts. Like the barrel on your favorite bolt-action, they have life expectancies. Short barrels are a LOT harder on suppressors because of the huge blast & higher heat than you get with longer barrels. So, if you are cool with maybe wearing out the core at a much more accelerated pace and you are cool with the understanding the bullet stabilization might become an issue, go for it. I know some guys with suppressed shorties and they love them. I personally don't like using my 5.56 caliber suppressors on barrels shorter than 10.5".

Best of luck.

Mark
 
Re: suppressed 7.5" AR...

Gunner0812, like you I wanted a 7.5" suppressed and did a lot of research. I wanted to run an AAC M4-2000 on a Noveske 7.5". Now after I think about it I believe Ops Inc said they would warranty it. But most companies won't. Also, I don't know what your expectations are but I would think a 7.5" with a can is still going to be hella loud.
 
Re: suppressed 7.5" AR...

Also, I'm not familiar with ThunderBeastArms. I would call them and ask about their warranty on end cap strikes and blast baffle erosion. If you find out or anyone else knows please post. I just checked out their website and I heard my wallet start whimpering.
 
Re: suppressed 7.5" AR...

It would also prematurely wear on the can. Not only will you eventually get a baffle strike, the over pressure and amount of unburt powder leaving the barrel is hell on the suppressor itself. While it looks cool as hell, it really doesn't have any practical purpose.
 
Re: suppressed 7.5" AR...

thanks for the input guys, I didn't consider the warranty & excessive wear problems. i'm not worried about ballistics or practicality though, as I know it won't really serve much of a practical purpose
 
Re: suppressed 7.5" AR...

Remember that in a 7.5" barrel, you are not getting a complete revolution on the projectile before it exits, so it does not get stabilized very well.

The Thunderbeast can has been mentioned, there is also the AAC 762-SDN6 that is warrantied for 7" barrels. It has all iconnel baffles and will work for 5.56 guns as well.

Good luck on your search
 
Re: suppressed 7.5" AR...

I've heard this time and again, but it does not explain how a 4" pistol barrel can stabilize a bullet. As long as you have the required twist rate to stabilize a given bullet, the number of turns it makes while in the bore should not matter. I say 'should' because this is all magic voodoo, and there is usually no good explanation for why a bullet is not stable when all other conditions are accounted for.
-Dan
 
Re: suppressed 7.5" AR...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ddavis</div><div class="ubbcode-body">I've heard this time and again, but it does not explain how a 4" pistol barrel can stabilize a bullet. As long as you have the required twist rate to stabilize a given bullet, the number of turns it makes while in the bore should not matter. I say 'should' because this is all magic voodoo, and there is usually no good explanation for why a bullet is not stable when all other conditions are accounted for.
-Dan </div></div>

A bullet does not instantly achieve a rotational velocity from twist rate and MV. The rotational velocity accelerates and the end result depends on rifling cut, barrel length, load, bullet construction & bearing surface...
It does matter.
 
Re: suppressed 7.5" AR...

Maybe not at all something you'd want, but ever consider doing a 9mm AR? A friend of mine has one that's got to be about 7.5" with a Gemtech can, and it's extremely fun to shoot, and very quiet.
 
Re: suppressed 7.5" AR...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Charlie Papa</div><div class="ubbcode-body">Maybe not at all something you'd want, but ever consider doing a 9mm AR? A friend of mine has one that's got to be about 7.5" with a Gemtech can, and it's extremely fun to shoot, and very quiet. </div></div>

Yea I have thought about it, however I don't feel like spending all the extra money for 9mm conversion (mags, mag block, BCG, 9mm can, etc). I already have most the parts to put together a 5.56 one, so it would cost me a lot less.
 
Re: suppressed 7.5" AR...

yelp. either go 10.50 barrel length or longer with the .223 it is only a matter of time, before a catastrofic baffle strike happens. I use a 11.5" and go to a little bit faster powder, and a minimal load for the rifle, 4198, 55 grs, something like 600 rounds through and no bad blast chamber erosion yet. Although it is a .30 caliber can. makes a big difference.
PM for more info
 
Re: suppressed 7.5" AR...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Texasshooter30</div><div class="ubbcode-body">yelp. either go 10.50 barrel length or longer with the .223 it is only a matter of time, before a catastrofic baffle strike happens. I use a 11.5" and go to a little bit faster powder, and a minimal load for the rifle, 4198, 55 grs, something like 600 rounds through and no bad blast chamber erosion yet. Although it is a .30 caliber can. makes a big difference.
PM for more info </div></div>

The 7.5" guns are pretty hard on cans- aside from reduced stability, most good suppressors are design optimized for a barrel length in the middle of the barrels they will be used on. The M4-QD for instance was designed for a 14.5" barrel. Logically speaking this is the correct way to design a product- not for 2% of end users, but for the 98%.

So when people put a can on a 10.5" gun, that's cool, because it's not too far outside design optimization. However 7.5" guns are more outside, so the optimal can for a 7.5" would be one that was way overbuilt for other calibers- like a 26 ounce thread mount from coastal or something like that- a suppressor who's heft would relegate it to a less desirable status with the 98% who don't have 7.5" guns.

The high performance suppressors on the market like the M4-QD 212, and others are not intended for 7.5" barrels so it's like running a set of tires with bad alignment - the parts wear out prematurely even if you don't have a catastrophic failure.

 
Re: suppressed 7.5" AR...

Anyone have an idea how loud one will meter even with a can? I'd bet my shoes it won't be hearing safe, just curious what kind of numbers you'd be looking at.
 
Re: suppressed 7.5" AR...

I agree with the others. A 7.5 is built for maneuverability and CQB work. Adding a suppressor defeats that purpose and the extent to which that weapon will be "suppressed" is questionable. Go 10.5 with the suppressor. You'll love the balance as well.

10.5
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7.5...you won't want to extend the length in a rifle caliber with that suppressor.
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