Best AGB for suppressed SBR's?

[earthquake]

Finally went to the shop/range that is holding my can until AFT releases it and sent some rounds through it. It ran my 10.5" pretty well except for a lot of gas in my face. So, I talked to the folks at the range about it and they mentioned a gas-buster charging handle. (they don't sell any of the stuff they mention, which is weird because they sell a ton of cans)

Never heard of the gas-buster. What about a Adjustable Gas Block? I was doing some reading on those and the superlative arms got high marks: https://www.brownells.com/manufacturers/superlative+arms+llc/index.htm

The JP stuff also get high marks as well from this article: https://thegunzone.com/best-adjustable-gas-blocks/

Anyone have direct experience with them? Or would the gas buster CH be all I need? Or both? Not sure if I should go cut-off or bleed-off.

Gun ran fine, only had one misfeed, but lots of gas in the face. YHM turbo-K, 10.5" barrel, ammo was just AE 55-gr and a few handloads I had brought with me of 77-gr. Would like to run it suppress all the time.

Thanks

 

[_Windrider_]

Finally went to the shop/range that is holding my can until AFT releases it and sent some rounds through it. It ran my 10.5" pretty well except for a lot of gas in my face. So, I talked to the folks at the range about it and they mentioned a gas-buster charging handle. (they don't sell any of the stuff they mention, which is weird because they sell a ton of cans)

Never heard of the gas-buster. What about a Adjustable Gas Block? I was doing some reading on those and the superlative arms got high marks: https://www.brownells.com/manufacturers/superlative+arms+llc/index.htm

The JP stuff also get high marks as well from this article: https://thegunzone.com/best-adjustable-gas-blocks/

Anyone have direct experience with them? Or would the gas buster CH be all I need? Or both? Not sure if I should go cut-off or bleed-off.

Gun ran fine, only had one misfeed, but lots of gas in the face. YHM turbo-K, 10.5" barrel, ammo was just AE 55-gr and a few handloads I had brought with me of 77-gr. Would like to run it suppress all the time.

Thanks

An adjustable gas block on a10.5” SBR is a waste of time money and energy. The reality is this, nothing you do will alleviate the gas in your face in a 10.5”. It kinda just is what it is. A piston 10.5” might be the alternative to a DI.

 

[earthquake]

An adjustable gas block on a10.5” SBR is a waste of time money and energy. The reality is this, nothing you do will alleviate the gas in your face in a 10.5”. It kinda just is what it is. A piston 10.5” might be the alternative to a DI.

Ah, ok. Good to know.

 

[_Windrider_]

Ah, ok. Good to know.

Of course that’s just one guys opinion.

 

[Huskydriver]

I mean an agb will def be less gas than a non....

I run superlatives on everything. Tune it to the can and load and forget it

 

[Desert_Racer]

I’m part of the #11.5masterrace, so take it for what it’s worth, but I disagree with tacticaldillhole’s statement (respectfully). I run an SLR gasblock on mine. It helps substantially, in my experience.

 

[earthquake]

Well I guess I can just try both the gas buster charging handle and a AGB.

Why not? It's only.....

 

[alamo5000]

An adjustable gas block on a10.5” SBR is a waste of time money and energy. The reality is this, nothing you do will alleviate the gas in your face in a 10.5”. It kinda just is what it is. A piston 10.5” might be the alternative to a DI.

An adjustable block is a waste of time and money if the goal is to eliminate gas in the face. If the goal is to help tune the rifle function and carrier speed it's not a waste of time at all. It's one of those 'could be' things depending on what you mean.

 

[Evintos]

Superlative Arms makes fine gas blocks (SLR does too). Adjustable gas blocks in gas reduction mode will reduce a lot of the gas going back into your system and delay unlocking (reduce the blow back gasses coming from your chamber and the amount flowing through the gas tube).

Combine it with a charging handle with the RTV silicone modification (old school way) or look for a charging handle design that has a enlarged (increased height and width) shelf.

Here's some info about restricted mode vs bleed off mode (from Todd Magee of Dead Air on another forum) -

 

[_Windrider_]

Superlative Arms makes fine gas blocks (SLR does too). Adjustable gas blocks in gas reduction mode will reduce a lot of the gas going back into your system and delay unlocking (reduce the blow back gasses coming from your chamber and the amount flowing through the gas tube).

Combine it with a charging handle with the RTV silicone modification (old school way) or look for a charging handle design that has a enlarged (increased height and width) shelf.

Here's some info about restricted mode vs bleed off mode (from Todd Magee of Dead Air on another forum) -

View attachment 7763924

its all true and very valid, except that the difference between a 16" barrel and a 10.5" barrel is profound. the amount of unburned powder and gas at the muzzle is much different which is why 10.5's spit fireballs. I just dont see the advantage of an AGB on a SBR or on any fighting rifle for that matter. on a precision type SPR or something yeah for sure. but not a gun you will be mag dumping on. it needs to be reliable cause its gonne get dirty as fuck.

FWIW i run Sperlative AGB's on all my AR-10's. They have a place. my opinion, and thats all it is, is that they are useless on a 10.5" SBR.

 

[TxWelder35]

If you want to spend even more money get a LMT E-BCG also

 

[Evolution 9]

I’ve found significant benefits from using an AGB (or better yet, a correctly sized gas port to begin with).

Most barrels are greatly oversized (according to Crane spec), so getting them back to “right” will reduce gas to the face and reduce malfunctions and wear due to excessive bolt carrier velocity.

 

[Evintos]

its all true and very valid, except that the difference between a 16" barrel and a 10.5" barrel is profound. the amount of unburned powder and gas at the muzzle is much different which is why 10.5's spit fireballs. I just dont see the advantage of an AGB on a SBR or on any fighting rifle for that matter. on a precision type SPR or something yeah for sure. but not a gun you will be mag dumping on. it needs to be reliable cause its gonne get dirty as fuck.

FWIW i run Sperlative AGB's on all my AR-10's. They have a place. my opinion, and thats all it is, is that they are useless on a 10.5" SBR.

Yeah that's one of those things that the OP will have to take into consideration. Does he/she need absolute reliable function across all conditions (slightly overgassed or overgassed is best) or want optimal performance and don't mind fiddling.

The best solution to begin with is a barrel with a properly sized gas port for his ammo and suppressor. AGB's at this point is really a "bandaid" (for lack of better term) fix. A reduced size gas tube like the BRT EZtune is another fix or heavier buffer is also another option (A5 length 5+oz buffers).

 

[frankxtc]

Here is another bit of data.
I run a 10.5” SBR (300 Blackout).
All handloads, subsonic 220gr, through a suppressor.
I put a AGB on it so I could adjust the cycling energy.
Turned down the gas quite a bit while testing loads.
Now cycles perfect w/ the Titanium BCG.
Assembled it with a “gas buster” charging handle, no gas complaints.

 

[_Windrider_]

Here is another bit of data.
I run a 10.5” SBR (300 Blackout).
All handloads, subsonic 220gr, through a suppressor.
I put a AGB on it so I could adjust the cycling energy.
Turned down the gas quite a bit while testing loads.
Now cycles perfect w/ the Titanium BCG.
Assembled it with a “gas buster” charging handle, no gas complaints.

But subsonic doesn’t have as much powder as a normal load. I bet the same setup with full power would yield a different result. It’s likely you are burning all of the powder not spitting it out the front end like a 62 gr 556.

 

[silentwoods]

My DD mk18 is fine with a 4.5" can. My 11.5 stag bbl was better.
My 12.5" noveske CHF barrel is tits.
They all have a non adjustable block.

But, I always shoot outside and I move around. Probably a big part of it.

So I'd imagine your gas port is larger to accommodate weaker ammo. Which is common sadly.

 

[Quiet6.8]

I’ve been toying with a RifleSpeed AGB the past few range trips and it’s been very nice. Incredibly easy to tune, tool less.

 

[Lunchbox27]

Of course that’s just one guys opinion.

Your opinion matches my experience.

Adjustable gas block, Raptor handle, even did the gasket trick. Just the nature of the beast. Not an issue outside, but indoors its a gas bath.

Every can is different though. I run an Omega and it has a lot of back pressure. OSS can’s will probably do better.

 

[Darkside-Six]

I have a JP adjustable gas block on my 10.3” MK18. Works great. Paired it with their silent buffet system and it’s very quiet, not over gassed, and quiet as hell. You can also get adjustable BCG’s but I have no experience with those.

 

[KYAggie]

Here’s what I did to elevate the gas issues on my suppressed SBR. Works great.

.750" Adjustable Piston System - Pistol Length - Solid - Melonited - Low Pro - AR15

SKU # SABO-PS-P750SM The Superlative Arms patented “Bleed Off”, Gas Piston System for the AR15 platform adjusts the gas flow by bleeding the gas out of the block instead of restricting the flow like conventional adjustable blocks. Results: The pressure used in the block is reduced only to the...

suparms.com

 

[GUNNER10]

Finally went to the shop/range that is holding my can until AFT releases it and sent some rounds through it. It ran my 10.5" pretty well except for a lot of gas in my face. So, I talked to the folks at the range about it and they mentioned a gas-buster charging handle. (they don't sell any of the stuff they mention, which is weird because they sell a ton of cans)

Never heard of the gas-buster. What about a Adjustable Gas Block? I was doing some reading on those and the superlative arms got high marks: https://www.brownells.com/manufacturers/superlative+arms+llc/index.htm

The JP stuff also get high marks as well from this article: https://thegunzone.com/best-adjustable-gas-blocks/

Anyone have direct experience with them? Or would the gas buster CH be all I need? Or both? Not sure if I should go cut-off or bleed-off.

Gun ran fine, only had one misfeed, but lots of gas in the face. YHM turbo-K, 10.5" barrel, ammo was just AE 55-gr and a few handloads I had brought with me of 77-gr. Would like to run it suppress all the time.

Thanks

With the ATF going to E Forms, I think you may want to consider some of the new lower back pressure cans. I am fan of the gas buster but its not really a game changer, the Adjustable gas solutions can cause more issue than solve if not set up properly and maintained.

 

[Not_A_Llama]

Superlative is the best from a mechanical perspective, and if bleed-off works for you, that's a handy and unique feature not found anywhere else.

Most barrels of any length, but particularly 10.5, are grossly overgassed. They have to be, because the barrel manufacturer does not control the other components used in the gun, and cannot gauge for variations in components. Put in your components, give enough gas so your system is *barely* working and you know what it needs, then dial in extra to suit your experience and conditions. Two extra clicks of gas past "barely functioning" in my setups provides a bulletproof functionality while significantly reducing gas-to-face and violence of cycling.

Also consider an LMT enhanced carrier. The delayed cam pin geometry and extra ventilation makes a huge difference to me in terms of cleanliness and gas-to-face.

PRI Gasbuster, RTV silicone, the rest as needed/wanted.

 

[MSTN]

Nailed it. That's how you do it. Well said, too.

All this got figured out a long time ago.

PRI Gas Busters work pretty well, plain and simple. It's just about the only gun part I used 20 years ago that I still use. Reason - No better choice in a charging handle for reducing blowback. Yes, you'll still get some gas up your nose and in your eyes.

The suppressor itself is responsible for more gas in the face than a direct gas operating system. Suppressed piston guns also dump gas back on the shooter.

With one exception I know of, most AR's and most AR' barrels - even all of top shelf name brands - are way over-gassed primarily so that they'll run with cheap ammunition. Reason: Manufacturers simply don't want to have to listen to the whining of customers who are budget limited to buying the cheap stuff. These rifles and these barrels end up being seriously over-gassed with decent ammo, but at least they'll run over-gassed. Who ever complains about that? Besides me, I mean...

LMT enhanced carriers do have "enhanced" cam pin geometry that likely does work (lotsa smart folks at LMT), but the most effective modification is they dump some of the excess gas.

I believe there is an optimum gas port size for both accuracy and reliability (or, with an adjustable gas block, gas port setting) for every barrel/suppressor combination.

 

[Evolution 9]

@MSTN

Which barrel maker is the exception?

BTW, you’ve built me 2 uppers and they’ve both served me well as LE patrol rifles.

 

[MSTN]

Glad to hear that!

Criterion barrels have the only reasonable gas port sizes I've run across. They all shoot considerably sub-MOA with capable ammo. They're easily the best bang for the buck I've encountered.

 

[earthquake]

Wow, a lot to consider here, guys. Thanks. So it sounds like to start, I can't go wrong with a gas buster CH and then I should start looking into something to reduce the amount of the gas port hole in my barrel by way of an AGB. Does that sound like a plan?

Thanks again!

 

[MSTN]

This looks quite unique and very promising. I plan to try one myself soon:

https://www.riflespeed.com

 

[_Windrider_]

This looks quite unique and very promising. I plan to try one myself soon:

https://www.riflespeed.com

Those are interesting

 

[bllistc]

I have a 9" faxon barrel in .300 BO with a superlative arms GB and a standard charging handle. Minimal gas to the face with supers and subs. Also have an 11.5" daniel defense in 5.56 with a PRI gas buster and a standard lo-pro gas block. That one sucks when it comes to blowback. Might be getting another superlative GB for that to try and tune that. Someone told me recently that the faxon gunner profile barrels are optimized for suppression but thats the first I've heard of it. It was very quick and easy to tune the gas block though so maybe?

 

[Quiet6.8]

This looks quite unique and very promising. I plan to try one myself soon:

https://www.riflespeed.com

I put one of these on my 338FED upper, it was built to be run suppressed 100% of the time. Had the rifle tuned in 4 shots.
The GB has 12 different settings, and comes with an additional plunger for even more fine tuning. Easy to take apart, and can be cleaned while on the barrel. NFA Review has a review on his YouTube channel.

 

[thedude824]

An adjustable gas block on a10.5” SBR is a waste of time money and energy. The reality is this, nothing you do will alleviate the gas in your face in a 10.5”. It kinda just is what it is. A piston 10.5” might be the alternative to a DI.

Thats absolutely ridiculous. Im just going to pretend this is sarcasm or trolling. That said, if you plan to run it suppressed all the time you dont really need anything special. My 10.5" is also suppressed 100% of the time. Its actually my wife's gun. We are taking a couple classes early next year and I wanted her to have a rifle that she could get used to. We went through half a dozen manufacturers to find glasses that wouldn't mess up her eye lashes. She is extraordinarily picky. To tune it I put the can on it and fired one round at a time until the bolt held open on an empty mag. I then did 2 more clicks. I probably haven't put more than 200 rounds at a time through it. The suppressor will get the receivers very dirty. Even unfired rounds in the mag are filthy. The gun is incredibly smooth shooting. I get no gas to the face. Ive got a regular Radian Raptor charging handle. Ive got 6 ARs. 5 of them have adjustable blocks. All of them are very smooth shooting and I have zero gas to the face. In fact, until my most recent build with a fixed block and Radian SD I had never experienced gas to the face. With the Radian SD the gas to the face is minimal. I went with a Bootleg adjustable bcg since with the can and fixed gas block the BCG was getting slammed around pretty badly.
Back to my wife's 10.5", I have an Aero adjustable gas block and I still do a cursory cleaning and rotate the adjustment after each time shooting it. I just like to keep my stuff in tip top clean shape.
Choose a gas block you trust. If you want to leave the gas settings even higher to ensure reliable function after substantial round counts or adverse conditions then a vented charging handle would ensure no gas to the face. If you are getting gas to the face with an adjustable gas block than you haven't set your gas block appropriately.