I really appreciate the thoughts guys. And I can't even explain how happy I am to be here in good health.

I've ruled out barrel obstruction because there was absolutely no barrel damage. I've seen guns with barrel obstructions that get shot. In all of them, there is some sort of evidence whether a barrel bulge or a ring in the barrel where the obstruction was. Borescope showed a clean bore with almost no fouling (30rds thru the gun since cleaning).

Right now, I'm kind of leaning towards the "detonation" explanation or a distraction at the press and I pulled the handle twice. But on the same note, when I tried to recreate the double charge (without a primer and taking significant safety precautions) my press wouldn't seat the bullet I was using. Even when I put some elbow grease into seating the bullet it still was significantly underseated. Wouldn't even come close to fitting in the cylinder. That kind of puts me leaning more towards the detonation explanation. Could have also been something crazy like a charge-and-a-half from the dillon, but it would certainly be a chance encounter - but thats really all it takes, one chance.

I will probably be calling S&W tomorrow and talk with them. They will probably want the last say on what really happened. All of the help I have received here has helped immensely. I feel much better at carrying on an intelligent conversation with them.

On a side note, I had an offer last night for a guy to buy it from me (local friend) so he can use it in his firearms safety courses that he teaches. Seems like a fitting retirement for the gun if Smith can't do anything for me.

Really appreciate the information and experiences from everybody here.