300 Blackout guys, I need your help...

[Jake]

I recently traded into an 8.5" 300 Blackout pistol. I took it to the range yesterday and ran 50 rounds through it, 40rds of 150gr FMJBT Federal American Eagle Supers and 10rds of 125gr HP Hornady. It was ejecting the spent cases all the way across the range, hitting the wall and then they were bouncing back to me. The spent brass was also slamming into the shell deflector on the upper, leaving brass all over it and denting the brass as well.

It has a regular buffer spring and an H1 buffer in it and running pistol gas. Would a heavier buffer help to eliminate this issue? I don't plan on suppressing it or running subs out of it(unless I can find subs for cheaper just for plinking) so I'd like to "tune" it to run on supers.

Here's a couple pics of the spent brass. Notice it's deforming every single round...


Did I wasn't my time picking the brass up? Is this still able to be reloaded? I'm not gonna reload it but I'm gonna sell it to someone who will once I accumulate enough brass.

And here's a picture of the brass deflector...

 

[Hoss]

I would try a heavier Wolff Buffer spring. It sounds like your bolt is beating your upper to death.

 

[Cudruln]

Yeah that's coming out a little hot. I would guess that a heavier buffer would probably take care of that.

 

[Willy Leadwell]

I’ve got several uppers that dent the brass and leave marks on the deflector, though maybe not that bad. I’ve just come to conclude that it’s “normal”.

 

[Jake]

I would try a heavier Wolff Buffer spring. It sounds like your bolt is beating your upper to death.

Yeah that's coming out a little hot. I would guess that a heavier buffer would probably take care of that.

Ummmmm, so do I need a heavier buffer spring or a heavier buffer? lol

@cmshoot @DarthVader I need y'all's help.

 

[cmshoot]

I would try a mix and see what gives you the best results. Get a heavier buffer, like an H2, along with a heavier buffer spring. Try various combinations using the 2 new parts and the 2 old parts, see what result you like best.

 

[Jake]

I’ve got several dippers that dent the brass and leave marks on the deflector, though maybe not that bad. I’ve just come to conclude that it’s “normal”.

I'm just afraid that it's gonna cause premature wear on my upper. That pic of the shell deflector was only after about 15 rounds.

This is pretty much the only AR that I have that I actually like and want to shoot so I don't want to fuck it up. Plus, it's gonna be my GHB gun(fits in my LBT 3 day assault pack) so I need it to be reliable.

 

[Jake]

I would try a mix and see what gives you the best results. Get a heavier buffer, like an H2, along with a heavier buffer spring. Try various combinations using the 2 new parts and the 2 old parts, see what result you like best.

I just did a little bit of googling and BCM recommends an H3 buffer for supers on their 9" 300blk upper so I'm gonna try that first. I'm on a budget right now after Black Friday and with Christmas coming up so I'm gonna try to order one part at a time and see what kind of results I get.

 

[Laufen]

Jeezuz, I'd definitely get an H2 buffer or even a adjustable JP. It looks like you could slow the bolt down quite a bit and still run subs reliably. My 10.5 doesn't even kick Underwood 115's out with that much authority.

I'm using an H1 in my PSA 10.5" and it kicks them out at a nice 4 O'clock angle about 10ft away.

 

[lesptr]

I’m doing this from memory and you guys know how I drink, but I seem to recall AAC recommending an H3 buffer back when I was building mine. My brass deflector looks like yours and my brass does as well. It still reloads just fine.

 

[Leshaire]

I just did a little bit of googling and BCM recommends an H3 buffer for supers on their 9" 300blk upper so I'm gonna try that first. I'm on a budget right now after Black Friday and with Christmas coming up so I'm gonna try to order one part at a time and see what kind of results I get.

Yo, I run a VLTOR A5-3 in one of my ARs. We can try that upper on this lower and see if it slows them down a lot before you go dumping money into it.

 

[Jake]

Yo, I run a VLTOR A5-3 in one of my ARs. We can try that upper on this lower and see if it slows them down a lot before you go dumping money into it.

Thanks man. I ordered an H3 Buffer last night from Primary Arms with a few other odds and ends that I had in the cart already.

 

[Leshaire]

Thanks man. I ordered an H3 Buffer last night from Primary Arms with a few other odds and ends that I had in the cart already.

Omg lol. Well nvm haha

 

[NWS]

Adjustable gas block?

 

[Jake]

Adjustable gas block?

Nope. Just a standard Aero Precision low pro and an 8.5" Ballistic Advantage barrel.

 

[NWS]

Nope. Just a standard Aero Precision low pro and an 8.5" Ballistic Advantage barrel.

I wasn't asking if you had one, I was asking if you had considered one. You're way over gassed.

 

[Willy Leadwell]

You're way over gassed.

If I had a nickel for every time someone said that to me I’d be able to buy @Jake an adjustable gas block.

 

[cmshoot]

I have some Sprinco heavy buffer springs, if you need one.

 

[Leshaire]

or a gas buster CH

 

[Laufen]

or a gas buster CH

That ainna gunna help.