Best Gas System for Suppressed AR

[sniperdoc]

When running a Suppressed AR w/ Subsonic Ammo, is a Direct Gas Impingement System more,or less, quiet than a Piston Gun?Is one more Reliable than the other? Is an Adjustable Gas Block desirable? Necessary?
I'd like to build a Suppressed Upper,probably in 300 BLK. I have no desire to shoot it unsuppressed. If I want unsuppressed 30 cal, I will shoot my AR10. Are there any Adjustments,Parts,or Modifications necessary for maximum Efficiency&Reliability?

Thanks,
Sniperdoc :fm

 

[Dockless55]

Gas piston is noisy as all get out. Least moving parts less noise. Bolt guns or single shot setting is best. Check subsonic hunter.com

 

[sniperdoc]

Dockless,thanks for the info! I've never shot an AR Piston Gun, but the moving parts statement makes sense!
I'm aware that w/Auto's, Semi or Full, have Cycling noise. That's one reason I want to maximize the efficiency of all other variables.

 

[Blksniper2000]

I would definitely get a adjustable gas block so you can tune the gas for that perfect balance for your gun

 

[chili17]

http://micromoa.com/?wpsc-product=the-govnah

 

[Pre-Ban_SMG_Model_B]

I guess the first question I would have is what barrel length are you thinking?

I shoot an Adams Arms 7.5 inch Suppressed SBR, piston driven, I prefer this setup.

I would be sure to get some sort of gas busting charging handle no matter which setup you get if you are going to shoot it suppressed. They do make a difference in the gas coming right back at you up your nose.

Later
Kev

 

[ChuckB]

I am building a new upper using the Govnah. I haven't used it yet but most users seem happy.

The WAR receiver is another option.

Gemtech now has a suppressor ready bolt carrier group.

Noveske had the SwitchBlock.

 

[dprice3844444]

noveske switchblock
http://www.shopnoveske.com/collections/parts/products/switchblock-clamp-on-5-56mm chili,any feed back on this?

 

[wtrski76]

Just built a 11.5" 5.56 upper on an innovative arms WAR upper with an SLR rifleworks adjustable gas block for suppressed/unsuppressed shooting. The SLR gas block is really nice to get the rifle dialed in to the ammo your are using without over-gassing, then the little switch/lever on the upper allows you to switch between suppressed and unsuppressed modes relatively easily, although it does get tough to turn after a couple of mags and I had to use pliers. You can tell quite a difference between the two settings on the upper. I believe this upper is optimized for 5.56 though and have never tried it with BLK.

Since you are not going to shoot unsuppressed and want quiet though, go with a 8-9" 300BLK, pistol length gas. Dare I say most of the barrels have a gas port size that is large enough to cycle unsuppressed subsonic, so by using an adjustable gas block, you could reduce the gas for less noise and still cycle suppressed. Personally, I don't have the adj. gas block on my BLK uppers because I shoot them both with and without a can. One is a 8.2 Noveske barrel and the other is a 9" AAC upper, both pistol gas. Also very quiet with subs and cans.

 

[sniperdoc]

Re: Barrel Length; I haven't really got that far yet. I'd like to keep the length (barrel & can) under 22", bit I want enough barrel to maintain accuracy. Do Subsonic Loads (factory) go Supersonic in longer (14"-18") barrels?

 

[TommyGun]

I am no expert but I don't think that a longer barrel would effect subsonic loads once you get out past 12" or so If I remember right velocity does not increase much with more barrel length. I also think that unless you are looking for marksman like accuracy out at 300 -500 yrd then your barrel length again is not going to matter. I can not say this from experience since I am just finishing up a 8" 300 Blk & 12.5" 308 and have not shot them yet but I see a lot of guys on a SBR thread saying they get fine accuracy from 8-10" builds.

 

[sniperdoc]

@ Tommygun, I would be satisfied w/ 2MOA & will probably shoot it (primarily) under 200 yards. I don't see using it @ extended range, unless it's what I have with me& need to make the shot. If I know I'm gonna be shooting Long Range, I will carry a Long Range Rifle, so the 300 will be for short to midrange shooting.

 

[ChuckB]

All else being the same, a longer barrel will be more quiet than a shorter one. In any caliber, but especially true of those dxesigned with a longer barrel in mind (7.62x51, 5.56x45 etc.)

That said, since you will only be shooting suppressed, and adjustable (adjust and leave, not WAR/SwitchBlock/Govnah) gas block should be ideal.

 

[Pre-Ban_SMG_Model_B]

All else being the same, a longer barrel will be more quiet than a shorter one. In any caliber, but especially true of those dxesigned with a longer barrel in mind.

This was my entire point when I was asking what length of barrel as I was trying to stick to the OP's original question.

My Adams Arms 7.5 piston upper, even suppressed, is loud enough where you don't even hear the piston working. It sounds like a regular 16-20 inch barrel un-suppressed.

Later
Kev

 

[ChuckB]

It is also why I am stick with a Title I AR suppressor host. Sure the short barrel is more handy with a can, but it partially defeats the purpose of the can.

 

[Dockless55]

As we are always told, length doesn't matter. Barrel quality and twist are the most critical factor. My .338 Thumper long or short barrel pictured on subsonichunter.com shoots MOA at 300 yards. Adjustable gas blocks are interesting, but too many are not working up good subsonic loads for their weapons. Long shots always remember windage and elevation.

 

[TommyGun]

My .338 Thumper

Tell us more.

 

[sniperdoc]

Re: Bbl length, I've seen T/C Contenders outshoot bolt action rifles,so I understand.
I want a bbl/can combo that is definitely hearing safe!

 

[wtrski76]

A DI SBR 300blk with subs and a decent can is definitely hearing safe. Most will meter in the mid 120s-low 130s. Yes, a fixed breech will be quieter at the shooter's ear, but it won't make much of a difference downrange.

 

[sniperdoc]

Would I be better with a 16" Bbl&a reflex can that gives me 22" total?