I've seen half a dozen of these involving several brands of rifle. So far as can be determined without extensive/expensive testing, the rifle was either fed an over pressure round, had a blockage in the barrel resulting in over pressure case rupture, or had the rifle fire without the bolt fully locked, leading to a case rupture due to lack of support.
OP, skip the dealer, he didn't warranty the product. Go straight to S&W and follow their instructions. BTW, you did clean the rifle before firing, right?
Beware of cheap ammo and handloads other than your own. Even your own if you're not very careful. I'd tend to think ammo related. Yes, the ruptured case will still be in the chamber and the BCG jammed.