Gunny,
I explained that my choke had been neglected (briefly, I swear.) and left some rust in the threads which I cleaned and did all the right stuff to. (Great grammer there, eh?)
A very knowledgable friend suggested that the choke tube was damaged and not flush in the barrel. That it was ripped out by that edge getting caught on the wad.
I don't think so, but be VERY careful with your gun at this point. Make SURE that choke tube fits absolutely flush as it should. Make sure the threads are tight and good. I will continue to investigate. But, it is obvious that there is lots of downstream force when that shot and wad are thrown out.
Guns, ya just gotta keep workin' on em.
Jake
