Well, crud. That's no fun.

The only times I've had an AR bolt lock up on me was while shooting TulAmmo. Tul has done that to me twice now. I'll shoot up what I have, but I won't be buying more. I've shot a lot of Wolf both Polyformance and Military Classic without issues. I've also never had the issue with any brass cased ammo.

Were you shooting Tul by any chance?