Please be safe and check your gn out thuroughl before this happens again. This would have been way worse with a heavy turkey load of buck shot.

The bolt came open, there is no way the base could have blown out like that if it had stayed closed. It is a matter of physics, the chamber didn't bulge, so what was inside of it can't be bigger around than what it is. Did the wad even make it out of the barrel? From looking at the hull it appears that most of the pressure went out the breech.

I would pull the trigger group out and see what it looks like. The bolt may have been all the way forward when you pulled the trigger, but it didn't fully lock like it is supposed to do to keep this from happening. Excessice crud or wear could cause such to happen.


I personally don't buy into the crimp issue.