wgungho
Member
I have a recently aquired Stag Mod 1. I'm the second owner and the first owner put <100 rounds through the weapon. I have fired several types of ammo through the weapon with only one presenting a problem. Using Privi, headstamped PPU-11, I get persistent failure to extract. This ammo is marked M193, 55 gr., BT. The extractor actually tears part of the rim from the casing. The casing remains completely in the chamber. A very gentle tap with a cleaning rod, and the casing drops free. It isn't "stuck" in the chamber at all. There are no marks or gouging on the spent casings, just the damaged rim. The chamber is clean and clear of any visible burrs. This rifle has M-4 feed ramps. Overgassing would seem the obvious cause to me, but my last Stoner weapon was issued to me in 1968, and it was a POS. I demanded and got back my M-14! I have limited experience with AR systems, but I do understand the mechanics.
Suggestions from other sources have included replacing the buffer with an H2 and heavier spring, using an O-ring on the extractor spring, using a heavier extractor spring, replacing the bolt carrier with a heavier, mil-spec piece, and polishing the chamber (which is chromed). Again, I have cleaned the chamber well. I assumed the possibility that laquered ammo was used, and cleaned for that, also.
The obvious solution would be to use other ammo. Regretfully, the huge majority of my .223/5.56 is this Privi, PPU-11. I've tried ammo from three different lot numbers, with the same results. No one that I've talked to has had anything bad to say about this ammo.
All observations are appreciated.
Suggestions from other sources have included replacing the buffer with an H2 and heavier spring, using an O-ring on the extractor spring, using a heavier extractor spring, replacing the bolt carrier with a heavier, mil-spec piece, and polishing the chamber (which is chromed). Again, I have cleaned the chamber well. I assumed the possibility that laquered ammo was used, and cleaned for that, also.
The obvious solution would be to use other ammo. Regretfully, the huge majority of my .223/5.56 is this Privi, PPU-11. I've tried ammo from three different lot numbers, with the same results. No one that I've talked to has had anything bad to say about this ammo.
All observations are appreciated.