300 BLACKOUT PROBLEMS

[MrShooter]

Trying to get this sorted out before I take my daughter hog hunting next weekend with her suppressed 300blk. I would appreciate anyone’s advice on the issue. I’m more of a bolt gun guy but some things require a gas gun... I’m wondering if it sounds like over gassing or something else. Every jam looked the same. See pics.

300Blk
8” barrel 1:7 twist (Ballistic Advantage)
Pistol length gas system
Carbine buffer
300blk specific PMAG
Remington 220gr Factory subs
All shots suppressed.

First mag went as follows..

1# Fired, ejected then failed to load next round by jam
Cleared
2#Fired, ejected then failed to load next round by jam
Cleared
3#Fired, ejected then failed to load next round by jam
Cleared
4#Fired, ejected then failed to load next round by jam
Cleared
5#Fired, ejected then failed to load next round by jam
Continued...

Fired another mag but with an H2 buffer for curiosity, I know subs need a carbine buffer to run.

All rounds fired & ejected but did not pick up next round at all. Had to hand cycle.
Seemed normal for subs and an h2?

 

[rc508pir]

Your upper have M4 feed ramps?

What buffer were you using before the H2?

 

[MrShooter]

Your upper have M4 feed ramps?

What buffer were you using before the H2?

Yes, Spikes Receivers. M4 cuts. Carbine buffer.

 

[GlockPride]

Gas ports lined up correctly?

 

[MrShooter]

Gas ports lined up correctly?

Yes. I marked and lined up port hole and barrel with pencil and blew air afterwards.

 

[lasher]

looks to be short stroking, i.e. under gassed. you running sub sonics, how does it run without the suppressor?

 

[Ignored Member]

The suppressor should create more blowback and make the bolt run faster.
It may be going too fast and catching the round in the middle instead of the base as it pops up from the mag. If so, you'll need a heavier buffer or an adjustable gas block or adjustble bolt carrier.

If the brass is ejecting at about 1 o'clock, it's overgassed.

 

[MrShooter]

The suppressor should create more blowback and make the bolt run faster.
It may be going too fast and catching the round in the middle instead of the base as it pops up from the mag. If so, you'll need a heavier buffer or an adjustable gas block or adjustble bolt carrier.

I was kind of thinking over gassed since it ejects well and I was running a can. Like the bolt is moving too fast for the mag if that is even possible???

 

[Ignored Member]

I was kind of thinking over gassed since it ejects well and I was running a can. Like the bolt is moving too fast for the mag if that is even possible???

Possible with a weak mag spring.

 

[MCVetSteve]

Possible with a weak mag spring.

This was my first thought as it’s the least expensive solution.