I have called Bushmaster about the gun. The good news is I was told that it would be repaired under warranty. The bad news, it may be 1-2 months as they are in the process of moving some of their operations. Bushmaster is paying the Fed Ex charges for shipping, so there is no cost for me.
The first two pictires show the crack in the receiver, and the last pictures show some of the brass. The top row is the split cases, the bottom row is "just" bulging cases. The Bushmaster service rep didn't think the split cases and split receiver were related. I can't swallow that. The cases didn't use to split after firing. Now the receiver is split and the cases are splitting. Looks like a duck, walks like a duck, sounds like a duck,,,,,,,,, well, you get the idea.