Hello all,

I have a rifle built around a 16" mid length gas, Larue Stealth barrel that will not lock back on last round with IMI M193(2009 prod) or Prvi Partizan M193 (2020 prod).

It will however lock back when shooting Norma .223  (brass case) or Wolf .223 steel case. 100% of the time. (over 500 rds tested between the wolf and norma)

It will lock back if I manually cycle the action with an empty mag.

It has a carbine buffer tube and an H buffer and a toolcraft milspec bcg.

Any thoughts?

Thank you for your time.

It’s so overgassed that the buffer is bouncing off the end of the receiver extension so hard that bolt is closed before the mag follower has time to lift the bolt catch.

From what I've read it does appear the Stealth barrel has a very large gas port.  Would a BRT gas tube be a smart test or a different buffer spring?

ETA: Just going to order a BRT gas tube.  

BRT gas tubes are a great fix for overgassing.
They make the gun very pleasant to shoot.

The BRT tube is the best way to fix it IMO. I’m not big on adjustable blocks.

Yeah, it sounds to me like it's severely over gassed. I'm not. Razor about adjustable gas blocks myself, but thought I'd try out the riflespeed.

It is very robust and doesn't appear to suffer from what others do, but it's around $200.

Like others have said, slap a BRT tube on there.

Why Larue ports their barrels as huge as they do is a mystery to me. Maybe somebody should tell Mark people do other things than shoot unsuppressed hand loads from a bench with their rifle.