3 weeks ago we had a case burst in one of Pappabear's LMT MWS AR-10s.

Curious to get some thought on this since it appears that the case burst out of battery. At first I thought the case neck separated, but on further review, the case fire formed about 1/4" out of battery which makes the brass appear to have no neck.

The barrel and lower appear to be ok, but the upper receiver and mag were effed up pretty good. LMT took the upper back to inspect.

The round that burst was the tail end of an old lot of 168 SMKs, again, loaded with a chargemaster. And no other rounds had any signs of pressure.

Firing out of battery is nearly impossible, but will a kaboom allow the bolt to unlock before the case fails? A friend thought possibly a half/light charge could have been the issue.



Brass was MEN which had already been fired at least once with the factory loading.

Barrel obstruction does NOT appear to be the issue. We were slow firing long range and didn't have a missed impact on the previous round, and the suppressor suffered no damage.