Ok, just got off the phone with my friend, here's the breakdown of what I know so far.
Less than a year old 3.5" sx3
Shooting 3.5" blackclouds
The gun fired the first round and locked open with the new round in the carrier. He hit the bolt release and chambered the next round. When he fired, it doubled and ended up with the entire case of one of the rounds in the barrel with the rim rolled back. Receiver is cracked, bolt carrier is cracked in pieces. There was powder burn on my friend hand and finger. He was guiding at the time and it scared the hell out of his clients!
It's being shipped back now so we'll see what happen.
Rudi - I was just asking for everyone's guesses because I figure people like to guess what happen to guns that blow up. I'm not looking for any useful information, just random brain farts from everyone and see if someone get sit right when we hear back from winchester.