300AAC pistol gas system?

[67 LS1 Camaro]

Im starting a new AR build in 300Blk. Planning to play with supersonic and subsonic loads, with whatever heads and powder I can get my hands on. Would it be wiser to go for a pistol gas system with and adj. gas block ?

[Bryan 45]

I have a 16" DoubleStar barrel (carbine gas length) that cycles both supers and 220g Rem factory subs. I've shot 150g and 110g supers using Lil' Gun and it doesn't seem overgassed, it operates very smoothly.

FWIW.

[usp45ss]

I've got a Daniel Defense barrel with carbine length gas on it for my build. It will function reliably with 220 subs and a can but will short stroke without the can. Supers work fine. I've got a carbine buffer and a m16 carrier. It probably needs a little more break in on it and it will be fine.

A lot of guys like H110 for supers and AA1680 for subs. Needs a little more gas volume to work the AR.

A pistol gas with an adjustable block wouldn't be a bad idea. It should work fine either way.

[mic2377]

Get a pistol if you want to play around with quiet sub loads - it gives you more latitude. Otherwise, if you are willing to 1680 for subs, and/or have a can, the carbine is fine. I have found that the carbine gas 16" stuff is considerably smoother shooting than pistol gas when using supers (I have owned both.)

Pistol gas with adjustable block is the best solution as long as you run a good block.

[67 LS1 Camaro]

Get a pistol if you want to play around with quiet sub loads - it gives you more latitude. Otherwise, if you are willing to 1680 for subs, and/or have a can, the carbine is fine. I have found that the carbine gas 16" stuff is considerably smoother shooting than pistol gas when using supers (I have owned both.)

Pistol gas with adjustable block is the best solution as long as you run a good block.

Thanks, that is what I was thinking, and will go with a Syrac adjustable block if I do..

Now lets say if I got a carbine length gas, and the action starts to short stroke with sub loads, would a lighter BCG and/or lighter buffer cure the short stroking?

[shooterready]

Get a pistol if you want to play around with quiet sub loads - it gives you more latitude. Otherwise, if you are willing to 1680 for subs, and/or have a can, the carbine is fine. I have found that the carbine gas 16" stuff is considerably smoother shooting than pistol gas when using supers (I have owned both.)

Pistol gas with adjustable block is the best solution as long as you run a good block.

Thanks, that is what I was thinking, and will go with a Syrac adjustable block if I do..

Now lets say if I got a carbine length gas, and the action starts to short stroke with sub loads, would a lighter BCG and/or lighter buffer cure the short stroking?

If you're going to run an adjustable gas block, just bump your gas port size up a touch. I'm running an 8.5" CMMG (pistol gas) with KX3 pig (gas port is now .125"). Runs 145gr M80s at 1065fps perfectly. Faster stuff gets a couple turns of the Syrac gas block.

[mic2377]

You can try lots of tricks to make the carbine gas stuff work better. This includes a reduced power action spring, LMOS carrier, and other stuff. However, this all reduces reliability. When I say carbine gas won't run with other powders/loads, I mean that when the limitations I mentioned above occurred with a standard weight carrier (semi-auto), a standard GI CAR buffer, and standard CAR spring. Another option is to open the carbine port to .125, as most ship with a port size of .100-106. I personally mic'ed my Wilson Combat barrel to be 0.106 This can help somewhat in the cycling department.

I guess you could really go big on gas port even for a pistol gas - but for a pistol-gas barrel, a gas port in the 0.93-0.95 should be all that is needed to run just about any subsonic load you can think of, as long as the bullet weight is 180+ gr. I personally think going any bigger than this on the port is not good, because it makes getting the gas setting critical to avoid hurting parts, instead of just reducing recoil. Also, if the port size is reasonable, you can go non-adjustable gas and just stick in a heavier buffer if you want to shoot supers.

YMMV on all of my above comments. I have played with the 300 BLK for awhile now. No matter what - a pistol gas with a adjustable gas is a great way to go!

[Rifleshooter24]

How about a pinned Lo pro pistol gas system such as the noveske? Would this be really over gassed or a reliable alternative for both subsonic and supersonic without going the adjustable route? I don't want to use an adjustable gas block if I can help it. An added potential failure point.

[shooterready]

The Noveske gas block has nothing to do with it being under or over gassed. It is the port diameter and the length of your gas system and barrel (dwell time). Like mic2377 said, you can play with buffer and spring weights, but nothing is better than going to an adjustable gas block, IMO. Not sure why so many, poo poo, the adjustable system. If done correctly, they will be just as reliable as a fixed system.