I've had this AUG A3 M1 for a bit now, round count is somewhere between 500 and 1000. The gun has always operated fine, except the bolt would fail to lock back after the last round maybe 1 out of 3 times. This would happen with Steyr and Magpul mags. Ammo used is milspec brass case M855, M193 and Wolf Gold, no steel case.
For the past couple hundred rounds I used the adverse gas setting, thinking it just needed breaking in. It seemed to work and I can't recall any instances of the bolt not locking back. Fast forward to today and I turn the gas back down to normal and hit the range. The bolt failed to lock back on 2 out of 3 mags.
I get home and strip the rifle down. I check the normal stuff. Piston has all gas rings, trigger pack is properly installed, rifle is clean, etc, etc. Then I notice the plate that locks up against the barrel seems to be getting hammered on and pushed out?
Attached File
Not really sure what the issue is here and if this related to the bolt not locking back. Any of you guys seen this before? Probably going to send some pics to Steyr and I would imagine they will want me to send it in. Bummer, I hate getting a lemon!