A Call to 300 Blackout Users

[Cavtrooper]

I am currently putting a 300 Blackout AR together and need some advice on the buffer and spring. It appears that the H2 buffer and GI spring seems to be what others are using but just wanted to see if anyone else has input on a buffer system based on my components.

Some specs to my build

-9.1” YHM barrel
-SB Tactical SBPDW brace
-YHM 30 Cal M2 Phantom Suppressor

Would like to shoot sub and super, suppressed and un-suppressed.

Is there a one size fits all for buffer and spring?

Thanks,
Johnny

[getsum]

Doing something similar except started out with a bone stock PSA rifle in .300BO. Going to make some loads with 165gr BTHP with 11.6gr of IMR4198 which should get in the area of 1050fps. Using a AAC762SD can. Would like it to cycle with out the can...will update when it all comes together.

[harleypower69]

Built mine off a Sig 300 Blk pistol. Went the SBR route and using a AWC PSR can. I added the H@ buffer and GI spring just as you mentioned. Runs like a top both suppressed and unsuppressed and eats everything from 110 gr to 220gr. You will be fine with that set up.

Chris

[Cavtrooper]

Right on! Thanks for the info!

[eodinert]

Gas port size is kind of a thing...probably more so than buffer and spring. If the gas port is right, you can use a standard carbine spring and buffer, and it will work fine.

The answer to this question tends to be 'try what you've got, and see how it goes'. Buffer weights and springs can be a decent bandaid to dial in a rifle.

[Tim McBride]

The H2 Buffer and GI spring are a good start. As eodinert stated, gas port sizing is also an important feature.
If you plan to use subs and supers in both supressed and unsuppressed, understand that to use unsuppressed subs reliably the gun will be 'gassy' with supressed supers. An adjustable gas block or adjustable bolt carrier may help in your situation.

[Viper 1-26 INF]

I run an SLR Rifleworks Sentry 7 adjustable gas block on all my builds. Allows me to use my lower with Strike Industries' Viper PDW stock (proprietary buffer/spring) or standard carbine buffer tube with H2 buffer and standard spring.