PSA 300 AAC

[MadPick]

Unburned powder = muzzle flash. I'm failing to understand the problem.

[RocketScott]

I read that 300 BO was designed for a 10.5-11 inch barrels. Might be why people are getting unburned powder in the shorter 7.5-8 inch barrels.

This guy says 9":

http://www.thetruthaboutguns.com/2014/11/foghorn/ask-foghorn-questions-300-aac-blackout-rifle/

That's about what I had read from other sources too when I built mine, around 8-9". I went with 8.5" since KAK had a bunch on sale.

Right now I'm just shooting S&B 200grn but will start reloading with Berry's bullets once I have enough brass collected.

[RocketScott]

Unburned powder = muzzle flash. I'm failing to understand the problem.

More junk building up in the can

[beckdw]

Does anyone with a 7.5" or 8" barrel have issues with incomplete powder burn on .300 AAC BLK subs? I know that's an issue with short 5.56 barrels, but not sure if it would be different for .300 considering the loads are quite different.

Do I ever. I was considering starting a thread on it. I get a lot of powder all over the inside of the ARs. Yet, I lose velocity if I back off the charge...wtf?

What powder are you using?

Probably need something that burns faster. All 300BLK that I've seen use pistol length gas systems. Not a lot of time to burn everything up.

I run AA1680 because that is the only powder that I have found that will cycle my loads in the 7.5". I'm considering trying magnum primers to see if I can get all the powder to burn.

[OhShoot!]

Does anyone with a 7.5" or 8" barrel have issues with incomplete powder burn on .300 AAC BLK subs? I know that's an issue with short 5.56 barrels, but not sure if it would be different for .300 considering the loads are quite different.

Do I ever. I was considering starting a thread on it. I get a lot of powder all over the inside of the ARs. Yet, I lose velocity if I back off the charge...wtf?

What powder are you using?

Probably need something that burns faster. All 300BLK that I've seen use pistol length gas systems. Not a lot of time to burn everything up.

I run AA1680 because that is the only powder that I have found that will cycle my loads in the 7.5". I'm considering trying magnum primers to see if I can get all the powder to burn.

Magnum primers sound like a great idea.

[Yondering]

I like the 300 Blk and load a lot of it, but 7.5" is shorter than I want. My first AR (back when the 300 was new) was an 11" 300 Blk, which I later shortened to 9". 9" works pretty well, but lost some significant velocity from 11" with supers; more than I expected based on the numbers posted online.

For subsonics only, it doesn't matter too much, except that it'll be a little louder for a given suppressor and load than a longer barrel would be.

[beckdw]

[quote="Guns4Liberty"]Does anyone with a 7.5" or 8" barrel have issues with incomplete powder burn on .300 AAC BLK subs? I know that's an issue with short 5.56 barrels, but not sure if it would be different for .300 considering the loads are quite different.

Do I ever. I was considering starting a thread on it. I get a lot of powder all over the inside of the ARs. Yet, I lose velocity if I back off the charge...wtf?

What powder are you using?

Probably need something that burns faster. All 300BLK that I've seen use pistol length gas systems. Not a lot of time to burn everything up.

I run AA1680 because that is the only powder that I have found that will cycle my loads in the 7.5". I'm considering trying magnum primers to see if I can get all the powder to burn.

Magnum primers sound like a great idea.[/quote]Yeah, the nice thing about subs is you don't have to worry about pressure as much.

[Waw44]

Resurrecting an old thread. Does anyone have experience with 300AAC without a suppressor in a PSA 8.5" stock upper? I'm thinking of one of their upper kits to build my first AR pistol.

[RocketScott]

I don't recall the exact specs of my upper but you should be fine with what they put together

You might need to swap the buffer out, that's all I did to get mine running well. No adjustable gas block needed

[beckdw]

My dad has the PSA 8.5" 300 Blackout pistol. Runs like a top at 1050fps with 10.5gr of AA1680 under a 203gr bullet.