Suppressor considerations on semi-auto .308

[GregSmith]

Totally new to suppressors. I want to put one on my rifle for some long-range shooting. 20 inch barrel, full size BCG, adjustable gas.

1. What basic concepts do I need to understand before slapping a suppressor on a semi-auto rifle? (Over-gassing, poi change etc.)

2. Should I change anything with the buffer or BCG etc.?

3. What are some of the better suppressors for .308? (And what features make one better than another?)

I know this can be an involved topic/thread. Thanks in advance for your help and education.

[taliv]

things to understand

they are totally worth it, but:

they get really really hot and make everything else hotter. wear gloves or plan on resting it on something that won't catch on fire or melt

carbon gets in the interface between bbl and suppressor and acts like cement. can make it very difficult to remove after an extended range session. use plenty of anti seize.

you will most likely want to play with a heavier buffer to delay the bolt from opening. it will result in less gas in your face, etc. you will also want to caulk your charging handle. search for the thread on arfcom for instructions and pictures.

depending on the type of suppressor mount, you may see POI shifts as it heats up. you'll want to test it and know your limits or switch mounts. that's why i gave up on QD and do threads only now, but brake attached QD are very popular these days. you will also most likely see POI shift between can vs bare barrel. just know your shift and compensate for it. no big deal.

i'd pick a can based on anticipated firing schedule and budget.. old steel YHM cans are durable and heavy and cheap and heavy and will handle rapid fire, but they're also heavy.

thunderbeast are lighter, expensive and will handle rapid fire.

the new silencerco harvester is impressively light and impressively cheap, but I don't know how they will hold up over time or with harsh schedule

[Alita]

Gemtech, suppressors that mount to PWS/Ambush tactical comps

Advanced Armament Corp and Surefire are suppressor/mount comp combos

[ShooterSteve]

Turn off your gas! It's pretty rude if you don't. I can't speak for every one here, but my 16" dpms with a yhm is down right rude without an adjustable gas block.

[Tom Freeman]

Turn off your gas! It's pretty rude if you don't.

???

[ShooterSteve]

I've got a dpms 16" 308, with a non adjustable gas block. With a YHM can and supersonic ammo, it is very over gassed, enough that it is pretty rude to the shooter with bolt slap. I need to get a gas block for it and one for my CM, but I put so much money in ammo for load dev, optics and equip for PRS, that I'm about tapped out. I'm also pretty new to shooting with cans, so if you can offer any advice, I'm all ears. I do plan on shooting sub-sonic in it as deer season is coming quick. Thankfully we can hunt suppressed in NC.

[Tom Freeman]

Totally new to suppressors. I want to put one on my rifle for some long-range shooting. 20 inch barrel, full size BCG, adjustable gas.

1. What basic concepts do I need to understand before slapping a suppressor on a semi-auto rifle? (Over-gassing, poi change etc.)

2. Should I change anything with the buffer or BCG etc.?

3. What are some of the better suppressors for .308? (And what features make one better than another?)

I know this can be an involved topic/thread. Thanks in advance for your help and education.

1. Your rifle is going to get dirtier inside running a can. Mainly carbon and powder fouling is what you will find. Run it wet and all will be well.

Using a can will cause a little bit of over gassing, but it isnt the end of the world, I just press on and deal with it. I have a couple uppers with adjustable gas blocks, but they are set wide open right now.

Your POI will change. It wont change a lot, but it will change a little. The better quality cans will have a very repeatable shift.

2. On my 308/260 I am using a lightweight JP carrier and normal everything else. On my 223s I am using standard weight everything other than full auto.

3. I have a few flavors of cans. Thunderbeast, Shark and SureFire. Thunderbeast and Shark are Titanium. Very light and accurate. When I am doing a lot of high volume shooting I dont mind beating up my SF cans as they are steel. Thunderbeast makes a brake attach can that is top notch. My 338 Can is a BA. All my other TBAC cans are direct thread on cans. All are accurate. Shark cans come with interchangeable thread inserts which is a plus. SF cans normally attach via flash hiders or muzzle brakes.

[Chucky]

I shoot a Surefire SOCOM762RC on my 18 inch OBR with the adjustable gas block that Mark ships on his rifles. I have a 1/4 MOA shift with the suppressor on using the same POA. An adjustable gas block is necessary a lot of times with a .308. I use fireclean on the adapter and the inside where the suppressor goes over the quick detach mount and it allows the carbon not to build up on the mating surfaces as easily.

[redial]

Good info here and I'll only add that if you happen to be a lefty like I am, the direct impingement design will be unfriendly to you unless you're able to turn off the gas - but then, it won't be a semi-auto anymore.

Mark

[kujo929]

The overgas issue will be dependent upon your rifle setup. My JP LRP runs the same suppressed and unsuppressed gas wise. It is at the sweet spot where it runs 100% unsuppressed and couldn't be turned down any to run suppressed even if I wanted to. Socom 762RC getting a 1/2 mil repeatable shift.

[ccoker]

I run Templar Tactical ti cans

even the short Nemesis30 is rated for up to 300 Win Mag.

It has a QD system so I can run it on different setups including a flashhider mount on my 14.5 and a JEC brake on my 18" 3 gun rifle.

They also make a direct thread mount for it.

There is no POI shift or change with or without can.

I also have the 9" direct thread Archangel and have another Nemesis30 (5") and 7" Arc30 coming.

I like their cans a lot.

I get my first 308 AR10 in tomorrow, the new Wilson Combat and it is coming with a non adjustable gas block they say they have the rifle tuned to run with our without a can.

I am trusting they got it right.

Will find out this weekend.

[TonytheTiger]

I wish you best of luck with your new toy, but I'm having a hard time wrapping my head around a gas system optimized for suppressed and unsuppressed use at the same time.

[ccoker]

I tuned my 6.8 (WC) with an adjustable GB to run both suppressed and unsuppressed, I don't see why they couldn't do the same with the gas port size, bolt weight and buffer setup.

Bill is pretty picky and I doubt he would release it unless they got it right.

[hitman]

Check silencerco and feel free to pm me or email me.

[RangerTrace]

I shoot a Surefire SOCOM762RC on my 18 inch OBR with the adjustable gas block that Mark ships on his rifles. I have a 1/4 MOA shift with the suppressor on using the same POA. An adjustable gas block is necessary a lot of times with a .308. I use fireclean on the adapter and the inside where the suppressor goes over the quick detach mount and it allows the carbon not to build up on the mating surfaces as easily.

We run the same can on our 14.5" OBR patrol rifles. I would say get an adjustable gas block or don't do it at all. I'm a lefty so I really notice what comes out of the ejection port. The OBR is fine with the adjustable gas block. However, they bought all of us Gemtec cans for our 16" Bushmasters w/o the AGB and it's harsh for me. So much so, that I refuse to shoot it with the can.....

[ccoker]

I ran my new Wilson yesterday..

it ran 100%

with and without can and no gas blowback whatsoever

[Graham Smith]

Be aware that while there are a number of general things, different suppressors have different requirements and some work better than others with particular types of rifles.

Start at the other end of the discussion - start by choosing a suppressor that suits your shooting and then see what the supplier / mfg has to say about what you should be doing with your rifle. You'll have plenty of time to make any changes to the rifle before you get your can. Silencer Shop is a sponsor at a long range forum I frequent and they seem to be quite knowledgeable and carry a good variety of brands.

Edited December 22, 2014 by Graham Smith

[ccoker]

agree with the SS recommendation.

They are local to me and I do suppressor testing with them often..

They will steer you right

[littlehendrick]

If you have an adjustable gas block, you will have to figure out a setting that works best for you. If you plan on only running the rifle in quiet mode, then you can make the system run "softer" by closing the port off more. Depending on how far you take it, it may not run without the additional back pressure from the can. Again, if running suppressed full time, not an issue. Also, you did not specify if you were going to run a DI system, or a piston system (some people do it). If running a piston, your impulse will be different. The adjustability of the piston system would also play into your buffer choice. This brings me to point 2, buffer selection. If you have a non-adjustable gas block, you can play with your buffer to reduce the cycling speed of the bolt. Though not a precision rifle, I run an H2 buffer in my SBR regardless of if there is a can. When I had an 18" precision upper, I also ran a H2. The SBR will run a H3 with the can on, but feels sluggish.

In terms of point of impact shift-

It happens, more with some barrels than others. This is also true of changes with the mounting system. You mentioned that you are putting it on a semi 308, so I am going to assume that you want a QD mount can/muzzle brake. Some mounting systems lock up better than others. I have personally seen the AAC 51t mount not lock up tight, and have a tiny bit of can wobble. This leads to an unreliable POI shift. I have had good luck with my surefire can. It shifts no more than 1.5 mils.
Now you are probably asking what I meant by barrels causing POI shift with a can. This is caused by how concentric the bore is. Also, it depends on the profile of the barrel. A short, super heavy barrel will resist the leverage of the can on the end of the barrel. A long, light weight "hunting" barrel "bends" more under the weight.

"Best Suppressor"-

What is most important to you? Weight? Mounting? Sound Reduction? Cost?

Weight wise- titanium cans are hard to beat, but tend to be less durable. Thunderbeast Arms 30 cal can comes to mind. It is designed for precision shooting, and is fairly light weight.
Mounting - Direct thread or brake? I am awaiting my Silencerco Saker 762 to be released from NFA jail. I chose it because of the solid lock up (predictable POI shift) combined with an effective muzzle brake. It also is rated to 300 RUM. It is also rated for full auto. It is not the lightest, cheapest, or shortest can, but it fit MY needs.

Finally-

Go buy a cheap pot holder that will be on closeout from Christmas, it is a great tool to grab onto the suppressor after it gets hot. You will also need a suppressor cover, to keep the mirage manageable for strings of fire.

Good luck, and enjoy the addiction!

[The Happy Gila]

Before you fall in love with which ever can tickles your fancy the most, do yourself a favor and check out Thunderbeast Arms Corporation. Thunderbeast can tell you which of their cans will best compliment your platform in what you want to do with it.

https://thunderbeastarms.com/

[PatJones]

Thunderbeast cans are nice, but the brake attach models are more appropriate for a semi auto. The direct screw on models can loosen.

If you're using factory barrel threads, many rifles have a small radius at the bottom of the shoulder. This can be made to work with a brake that is glued on, but you will have problems with a direct screw on can. The can would only touch the shoulder on the radius and that doesn't provide enough friction to keep things tight.

Many AR style 308s have a small shoulder behind the threads that is insufficient to square up a suppressor. Most manufacturers specify a .050 shoulder, so the barrel diameter must measure .725 for a 5/8 thread. AAC makes a brake that squares up of from the front of the barrel for these smaller diameter barrels.

[CJW]

I just ordered a SilencerCo Saker 7.62 to go on…well, just about everything. It'll go on a DPMS G-2 as soon as I get one, and it will do extra duty for 300BLK and 6.5CM, including getting my 6.5CM bolt gun threaded for it. Heck, it will go on some AR-15s, as well. A couple of friends who are big into Stamp collecting have been raving about the Saker, and everything else I have read just backs that up.