In order to participate in the GunBroker Member forums, you must be logged in with your account. Click the sign-in button at the top right of the forums page to get connected.

Suppressed AR-15 and gas blowback

Kevin_LKevin_L Member Posts: 1,355 ✭✭✭✭

I'm still waffling on starting the tax stamp application so I can get some kind of suppressor for my noise maker AR. I've been reading about gas blowback when using a suppressor and the information has been spotty at best.

With a 16" barrel, what sort of gas blowback are we talking about? A face-full of eye watering nastiness? The gentle breeze of liberty? Something in between?

What have you folks experienced?

"...the right of the people to keep and bear Arms, shall not be infringed." 🍺 🇺🇲 🍔


  • mike55mike55 Member Posts: 2,830 ✭✭✭✭

    I do not have any experience with this BUT your "gentle breeze of liberty" comment is awesome! 😁

  • waltermoewaltermoe Member Posts: 1,781 ✭✭✭✭

    Now a days they call them suppresses, so I guess the older term I still refer to them a is silencer. You fill never really totally silence a pistol or a rifle, there will always be the mechanical sound of the bolt or slide moving. As for the blow back, think of it as a muffler on a car. The sound of the engine is surprised/ silence by the muffler but at the same time it is restricting the hot gases from escaping as fast. As the bullet passes each baffle in the silencer it is holding pressure back, there fore you will have more pressure forced back against the bolt. You will experience the chamber becoming more fouled and becoming dirty quicker.

    You will never totally silence a firearm. To do so would require a bolt action firearm and the bullet would have to be traveling under the speed of sound. And example. The reason a 22 long rifle round is louder than a 22 caliber standard round, the velocity of the 22 long rifle is going faster than the speed of sound, it’s not because of more powder.

    As far as hot gases coming back in your face, the gas will leave out the ejection port away from your face.

  • drobsdrobs Member Posts: 22,527 ✭✭✭✭

    You can get a gas buster charging handle that will help with that. I misplaced a couple of those charging handles somewhere in the house.

    It really doesn't bother me but it was bothering my friend's son that was shooting my Dead Air Nomad-L on an AR of mine.

    I learned a lesson with the Nomad-L. It's long and heavy. Check weights when buying a suppressor.

    Try not to over analyze to the point of inaction when buying a suppressor. I did exactly that for 10 years before buying 2 suppressors. For the amount of time you have to wait for the tax stamp, just get 3 suppressors. I did a 9mm can and a 308 can. I should've also bought a 22LR can.

  • drobsdrobs Member Posts: 22,527 ✭✭✭✭

    The least expensive way to mount a suppressor is direct thread. Each suppressor comes with a direct thread plate on the rear of the suppressor. If you want to use your multi-caliber suppressor on different rifles, Quick disconnect is the way to go.

    QD Adapters and muzzle devices is where you get screwed with suppressors. I like the idea of quick disconnect suppressor mounting system. However I don't like the price of a QD system. The adapter will easily run $250 to $300 and then you need to specific flash hiders that run $90 each to use that adapter.

    Example from Dead Air. I started with the KeyMo:


    KeyMo flash hiders run around $90 each. That adds up fast if you want to use your suppressor on multiple rifles.

    Visiting a gun shop I saw a neat product by Griffin Arms called an A2 Adapter. Theoretically you can use this adapter on any AR15 of AR10 that has an A1/A2 Flash Hider.

    Watching various videos l learned Griffin offers a QD Gate Lok version that is supposed to work with all "Nato Spec" A1/A2 Flash Hiders.

    I bought this gate-lok thinking I could use it on any of my 7 or so AR15's without needing to buy more $90 Flash Hiders. What a revolutionary idea. The problem is, it doesn't work.

    It locked on to my Windham (bankrupt) and my Bushmaster (out of business) A2 Flash Hiders. It didn't work on my 5 PSA rifles.

    The Rep for Griffin is on and he is staying quiet as to what A2 Flash Hiders will work other than Griffin's $100 flash hiders. I'd buy Larue A2 Flash Hiders if I knew they would work.

    I'm taking a gamble and buying a couple more Windham Flash Hiders. They might or might not work. Windham is still selling parts. They might or might not ship.

    At this point I wouldn't recommend Griffin.

  • FrogdogFrogdog Member Posts: 2,753 ✭✭✭✭

    Gas blowback shouldn't be much of a problem to worry about. In a previous job, we used suppressed 10.5" MK-18's. I don't recall any blowback issues. However, I will say this. The suppressor will help the rifle get dirty in a hurry, so be prepared to do a lot of cleaning.

  • shootuadealshootuadeal Member Posts: 5,226 ✭✭✭✭

    Yes, you get greatly increased back pressure, it is noticeably violent and it will eject your brass alot further than you are used to. The most common practice is to install an adjustable gas block, normally a fairly easy fix.

  • buddybbuddyb Member Posts: 5,224 ✭✭✭✭

    I saw a guy at the range using an oil filter adapter on an AR. I assume it was legal because it is a state owned range and always have a LEO safety officer watching over things. After a few rounds with the oil filter suppressor,the paper element in the filter started shredding and plugged the gas system of the rifle.

  • mstrblastermstrblaster Member Posts: 239 ✭✭✭

    I've read about this company called Silencer Central, I believe on the back of magazine covers. You can let them know what it is for, give them a deposit and they file all of the paperwork electronically. When paperwork goes through, you pay the rest and they ship you your can. I would think they would give good advise on all of the mechanics of making the can work for your application....

    To my mind it is wholly irresponsible to go out into the world incapable of preventing violence, injury, crime, and death. How feeble is the mindset to accept defenselessness, how cheap, how cowardly, how pathetic. Ted Nugent.
  • boogerbooger Member Posts: 1,452 ✭✭✭
    edited January 26

    The blowback is out the charging handle. Doesn't matter barrel length or type of suppressor, it's not fun. I went with Griffin Armaments SNACH (Suppressor Normalized Ambidextrous Charging Handle) and it helps a lot. Large safety glasses also help, it's the blast of gas to the right eye. I have several different uppers, different suppressors, always a problem, hate it.

    Next is to try try a bear creek side charging upper, I anticipate that to be a permanent fix. (No charging handle)

    And yeah, it really makes the gun filthy in a hurry.

  • NeoBlackdogNeoBlackdog Member Posts: 16,472 ✭✭✭✭

    You can also buy a piston driven upper to put your can on. That way all the gas stays out of the receiver.

    It's just money...

  • barbyrbarbyr Member Posts: 3
    edited January 26

    The Huxwrx hx-qd 556 and surefire socom556-rc2 are my favorite for the AR platform I can shoot both without hearing protection

    The huxwrx is more of your friend if you are concerned about blowback

    And yes there are charging handles that will help radian raptor sd and geissele airborne I also run a adjustable gas block

    Last year the earliest I got one out of lockup was 5 months the longest was a 7 months and I filed electronically

    But to answer your question its somewhere in between you are going to get gassed but its not that bad but I wouldn't want to shoot it all day

    The most fun you can have is suppressing a 22

  • dunbarboyzdunbarboyz Member Posts: 2,081 ✭✭✭✭

    If the neighbors aren't irritated when you are out blowing things up. Where is the fun in that?

  • yoshmysteryoshmyster Member Posts: 20,842 ✭✭✭✭

    If I could I'd start the process. You'll have like what a year wait?

    Like drobs mentioned be sure to pick up a can friendly charging handle (my choice Radian Raptor SD). And I'd get a easily adjustable buffer system like JP Enterprises captured spring system. Swap out a spring or add Tungsten weight.

    I'd put out a question. Will an adjustable gas block be helpful?

  • drobsdrobs Member Posts: 22,527 ✭✭✭✭

    Griffin's rep finally chimed in 3 days later. Aero Precision A2 flash hiders ($10) will work with their gate-lok adapter.

    "The aero precision A2’s work. They are probably made by Swissomation.

    Those units have diameters down at .860 or .861 (the bottom of the print), our devices target .8627 +-.0004”

    RE adjustable gas blocks: I haven't needed one yet for my AR's to run. Everyone says PSA AR's and most sub $1500 run of the mil ARS (S&W Colt etc) are over gassed. My 10.5 PSA pistols runs just fine with my DA Nomad-L.

    When that brace ruling went into effect, I deconstructed this pistol.

    Now that there are 2 injunctions out there to the brace ruling. This pistol will get the DA Nomad as soon as I have another flash hider:

  • drobsdrobs Member Posts: 22,527 ✭✭✭✭
    edited January 26

    My 2 Form 1 stamps for my suppressors took 11 months. I used the Silencer Shop Kiosk to apply.

    While that kiosk is an online function, the Silencer Shop prints everything out, reviews it, and mails it into the ATF. You pay them a fee for their services (hands on review) and for the stamp. The kiosk does make filling out the forms easy. You also do your fingerprints on the Kiosk. You still need to send in passport photos which my local dealer handled for me.

    Funny thing, the kiosk will give you a rating on your fingerprints. From good, bad, poor - redo. I gave up after trying multiple time and submitted "bad" rated fingerprints. My fingerprints and DNA for that matter are already in the "database" from my military service and DOD contracting. So my "bad" rated fingerprints didn't hold me back from getting stamps.

    One of the things that held me back from getting suppressors in the 1st place, was this whole registration of a trust vs registration as an individual. I still don't know the ins and outs of it. I registered my 2 cans as an individual. When I die, my SO or family can do another form with ATF to take possession of them.

  • drobsdrobs Member Posts: 22,527 ✭✭✭✭

    2 more thoughts.

    Suppressors get HOT like 950F HOT!!! Buy some welding gloves or high temp BBQ gloves. I picked up a pair of BBQ gloves that are rated to 400F from Walmart. You need to be extra careful as who or what that hot suppressor touches.

    Some suppressor fans state that once you suppress, you'll want to suppress everything. I didn't find that to be the case. Mostly because of the stupid expensive Key Mo flash hiders and accessories. Threaded pistol barrels are also stupid expensive.

    Re pistol mounted suppressors: You can shoot a couple rounds out of them b4 they get stupid HOT but you cant mag dump your pistol w/ suppressor, then put it in your shoulder holster. It will burn you. Shooting in my back yard / I need a holster for every handgun. There are holsters out there for suppressed pistols with the suppressor attached. They are kydex and require the use of a flashlight mounted to the pistol. I have this one for my G19 with Gemtec Lunar 9 and Surefire WML. It's stupid and I doubt I'll ever use it:

    Ultimately pistol mounted suppressor suck. There is a worry (rational or otherwise) that they will unscrew mid firing. They work better on a Pistol Caliber Carbine with a tri-lug mount.

    I'm also paranoid about these suppressors. For the most part they stay locked up. I'm actually tempted to get safety deposit box for my suppressors. I'm definitely not leaving a suppressor in the car on a road trip. I'll bring electronic hearing protection and an AR pistol or rifle with me on a road trip.

  • MobuckMobuck Member Posts: 13,685 ✭✭✭✭

    To address the 'gas in the face' issue: How this affects you will depend on how you shoot. Single shots with a few seconds between don't cause the 'gas in the face' issues. It's the 'battle rattle' rapid fire that tends to be the culprit.

    Our suppressed AR's are hunting tools not show off range toys. I/we have never noticed any gas in face issues.

    The majority of my suppressor hosts are Adams Arms piston drive conversions and I'm very pleased with the results. Far less fouling in the action and especially in the BCG(no gas channeled into the BCG) although there will always be some. Unfired rounds in the magazine will get dirty but don't cause functional issues. The adjustable feature is great. I can even turn the AR into a manually operated rifle for quieter performance.

    If I had only one suppressor on a single host, I'd go with direct thread. In some cases, it's a bit cheaper. Cuts weight by a few ounces. Cuts the built in tolerances of barrel to adaptor to suppressor insert. Really isn't a big deal to thread off/on if you pay a bit of attention. If a quick mount interface is your wish, YHM has a feature I like: the ratchet retention parts are part of the muzzle mount rather than part of the suppressor. If the ratchety parts get worn or damaged, it's an OTC replacement vs sending your muffler in for repairs.

    Silencer Shop and Silencer Central are both good choices. We have a Silencer Shop kiosk dealer within 40 miles which is handy. I did have some problems with the finger print feature on the kiosk but that was mostly due to having serious burns on both hands in the past. The good thing is, you get immediate feedback as to whether the prints are satisfactory rather than finding out after 3-4 months that the cards weren't readable by ATF and you have to start again. We do the photos at home and attach to the 'on-line' forms which include a 'signature' (I think that requires the use of a tablet or iPAD).

Sign In or Register to comment.