.300 Blackout gas system questions

[USAF_Vet]

What length gas system is recommended to a .300 blackout build?

I'm thinking of a 10.5" with a carbine gas hole, but saw a 16" kit at a decent price, but noticed it was running a pistol length gas system.

Is this normal for .300 BO? I can only imagine it would be to help cycle subsonic suppressed.

I'm going to Form 1 my 5.56 pistol, and get a Blackout upper with plans to suppress. Is 10.5 with carbine gas a decent enough set up for relaibility with and without a can?

 

[rbernie]

I can only imagine it would be to help cycle subsonic suppressed

Even supersonics can short stroke with the wrong gas system, due to the underbore nature of the cartridge.

I run a carbine gas system on some 16" barrels and a pistol gas system on others. The carbine gas system, even at 16" of barrel length, is picky on what it'll cycle sometimes if I get too goofy with my supersonic-only handloads. I have no experience with a suppressed 300AAC, but I would expect that the can will offset some of the loss of dwell from the short barrel.

Even so - I'd probably opt for the pistol length system but that would be a guess based on the consensus from folk that run cans and SBR's....

 

[yugorpk]

Do not run a carbine length gas system with a 10.5" barrel. You will be miserable. This isn't a 5.56 and pressure is MUCH lower at the port. Use the the pistol length system that comes with most , if not all , 10.5" barrels.

 

[USAF_Vet]

Good to know. I was thinking it had something to do with pressure and dwell time to reliably cycle the bolt. Just thought it was odd, 16" barrel with pistol length gas.

I found a 10.5 .300 barrel with pistol gas. Looking forward to my next build.

Thanks, guys.

 

[Bartholomew Roberts]

I've got a 9" with pistol gas - it runs perfectly supressed, unsuppressed, subs or supers.

 

[Elkins45]

Pistol gives you more versatility.