Supressing an AR-10

[just bill]

I'm new to the site and tried a search, however I am not used to the protocols, so if this is redundant forgive me. I'm buying a AR-10 for subsonic use. Can most any manufacturer be fitted with a .308 suppressor or are there ones that should be avoided? A couple years ago I had the idea to suppress a M1A, but most the subsonic applications left it a bolt action not a semi automatic. I have a huge quantity of 7.62 nato brass to use and reload, as well as swage my own projectiles. That's my reason I'm interested in an AR-10.

Thanks,
Bill

[johndoe3]

One thing you might think about with regards to a semi-auto 308 (I have one) is that you are not going to be able to fire it semi-auto with subsonics. Using the heaviest bullets, my LR-308 with 18" barrel sometimes successfully ejects a subsonic case, but the bolt doesn't go back far enough to pick up another round.

In essence, you will be firing subsonics from the AR-10 as a single shot bolt gun. If you heavily modify the AR-10 to operate subsonics in semi-auto, then your modifications will preclude you from shooting full power .308 from it without re-modification back to its original state.

Meanwhile, the 300 Blackout was designed from the beginning to shoot the same heavy .308 bullets in subsonic and to fire supersonics without modifications. I strongly suggest that you consider getting a 300 Blackout for extensive shooting of .308 bullets in subsonic semi-auto.

As far as suppressors go, any good .308 can will work (I use an AAC); although, some are very heavy and the better ones weight half as much hanging out on the end of your barrel. In shooting subsonics in semi-auto for maneuverability, you want a suppressor that weighs less than 20 oz and some are down in the 12 oz range. So look for a lighter weight suppressor.

[just bill]

Now this brings up a whole different approach. 2 uppers, one straight and one suppressed, that is if the significant changes are in the upper only. I would like to find more research on the upper modifications. I don't shoot that much that I need a really built up upper, however the idea of two uppers is doable.

[fishman]

I bet you could get a custom barrel made, with a short gas system (pistol or carbine). This in conjunction with an adjustable gas block could result in a gun that cycles supers and subs if you adjust the gas block between ammo changes.

However, you're better off shooting 300 blackout in an AR15 if you dont need/want the full performance of 308 supers. 223 brass is cheap and easy to come by and can be converted to 300blk.

Two AR 10 uppers would be more expensive but a better solution.

[hardcase]

If all you have is access to free 7.62 brass you would be much better off with a different host for suppressed use.

I have an AR 10 and a 30 cal suppressor. When compared to my 300 BLK, and a AR 15 platform the AR 10 gets really heavy. You can still use the lower for a 5.56 upper with a different buffer and spring.

Don't get a gas piston upper for subs. An adjustable gas block is helpful too.

You can buy already processed 300 BLK brass for 100/1,000 shipped on the 300 BLK web site and it last through many reloads.

[just bill]

I intend to have a dedicated .308 subsonic semi auto. I make my own (sewage) 308's from mild to wild. That being said, I am searching for a subsonic semi auto. I have a lot of 7.62 NATO and thought it was doable with the 7.62. If I read you correctly 300 BO, non gas piston works best. Recommend a recoil rifle I should look in to.
Thanks,
Bill

[JeffWard]

I wouldn't invest in an AR-10 for subsonic use, even if you own a TON of 308 brass.

The only advantage the AR-10 platform has in supersonics at long range.

In an AR-15, you can shoot anything up to 50 Cal bullets subsonic.

I'd sell/trade the 308 brass for 5.56 brass, and go with a 300BLK, or 458 SOCOM.

JW

[hardcase]

I intend to have a dedicated .308 subsonic semi auto. I make my own (sewage) 308's from mild to wild. That being said, I am searching for a subsonic semi auto. I have a lot of 7.62 NATO and thought it was doable with the 7.62. If I read you correctly 300 BO, non gas piston works best. Recommend a recoil rifle I should look in to.
Thanks,
Bill

Just go with old school, direct impingement brand of your choice. It is still gas operated (not recoil operated). I have both and the gas piston just does not work well with subs. Gas piston the carrier/bolt is shoved back by way of a rod to a gas block under the hand guard. Direct impingement the gas travels by way of a tube under the hand guard to the carrier/bolt. I hope this describes the process correctly. I'm not very good with firearms terminology.

[just bill]

I think I follow your thought, so if I get a 300 BO upper do I need to get an adjustable gas block and adjust it to the suppressor and just continue to march. The gun shop said pretty much the same thing, stay away from piston drive.

[fishman]

I think I follow your thought, so if I get a 300 BO upper do I need to get an adjustable gas block and adjust it to the suppressor and just continue to march. The gun shop said pretty much the same thing, stay away from piston drive.

you dont NEED an adjustable gas block, but it can make things even quieter. instead of using an adjustable gas block, you could just mess with the weights in the buffer.

i have an adjustable gas block, its the simplest way to tune an AR.

[just bill]

There is a new twist, while checking the suppressors, a Gemtech 300 BO upper jumped out at me.
How bout dat ?????