Hi guys,

Here's a bit more detail on the problem, hopefully the community can help me. I have a stamped lower and 2 SBR uppers. 10.5" AA 5.56 upper, and a 11.5" AA 7.62x39 upper.

The 5.56 upper shoots fine with/without suppressor.

The 7.62 on full gas won't pick up the next round in the mag. If i attatch my suppressor it will pick up the next round only full gas mode, not on the suppressor setting.

I think I need a heavier buffer to slow down the action for the 7.62 upper. I currently have a standard carbine buffer in my lower.  My goal is to keep a single buffer in the lower that will work with both Uppers.

I just don't know which buffer weight will work , please help. Thanks

Are you SURE its not under gassed with 7.62?

Sure sounds like an under gassed deal to me.

Will the 7.62 lock back after last round in magazine is fired?

After looking up the symptoms to under-gassed , it sure does seem like it. I didn't notice if it locked back on last round.

Assuming it is under-gassed, what should I do?

What buffer and spring do you have installed?
What ammo were you running?

It's under-gassed. you can shoot me an email at [email protected]