I shot my SBR with a 10.5" 5.56mm barrel the other day and noticed some particle blow-back once I screwed on the can.

This is the first suppressed set-up with which I have encountered blow-back.

The RTV "gas buster mod" helps some, but it was recommended that I get a Superlative Arms adjustable gas block w/bleed-off.

It allows you to shoot in standard (some or all gas through the gas tube), closed (no gas through the gas tube), or bleed-off mode (some or all gas out a bleed vent in the front of the gas block).
Standard and bleed-off modes have multiple positions so you can tune to your ammunition and needs. Once you know the requisite settings, you can switch between subsonic and supersonic ammunition.

YouTube reviews appear to bolster the manufacturer's claims.

Does anyone have experience with this gas block?

George

Getting a BCM Gunfighter charging handle stopped some of the gas blow back with my SBR.

There is nothing about the BCM Gunfighter charging handle designed to deflect gases and debris (unlike the PRI Gas Buster).

George

George, I use the PRI Gas Buster on my Rock River ARs and have never had a problem. Then again I do not shoot with a suppressor so your mileage may vary.

The only issue on an adjustable bleed off is making sure they are always clean to perform consistently. Maybe doing both will alleviate the problem.

Aside from all that, what suppressor are you running with?

Thanks. The Superlative Arms bleed-off adjustable gas block arrived yesterday; once I install it I will check its effectiveness versus just the RTV modification.

I've shot lots of suppressed rifles (up to .308 Win.) and never experienced noticeable blow-back, so I was bit surprised.

Shooting left-handed makes it a bit more objectionable.

And not a fun surprise at that...

Fortunately, I ALWAYS wear eye protection at the range (and when hunting with a gas gun).

George

Well, I am VERY happy to say the Superlative Arms bleed-off gas block works well.

Once installed, use the provided hex key to close it by turning the adjustment screw clockwise until it stops. Then, turn it counter-clockwise 4.5 turns to allow maximum pressure through the gas system.

To bleed off gas, turn it another 1.5 turns, load one round in the magazine and fire. If the bolt locks back on the empty magazine, you're done if that setting has reduced blow-back to your satisfaction.

I turned it another full turn counter-clockwise (7 from 'closed') and achieved that 'just right' setting of no blow-back, soft 'recoil', and proper function with that load.

I'm going to order more of them for my .300 BLK and .458SOCOM rifles.

George

Thanks for the update. I have never used one, but good to know it solves the problem. Will be interesting to see how it performs over time.

Is there any documentation on cleaning it?

There is no documentation, but you'd clean it with a pipe cleaner if needed. You can access the bleed-off vent from the front of the gun.



George

Looks easy enough to keep clean.