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
Whether the choke tube is flush or not is not the important factor. What's important is that the rear of the tube is bottomed out, tight against the shoulder in the barrel at the back of the hole, so gas can not get between the tube and the barrel. The front of the tube may or may not be flush with the muzzle. Extended tubes will not be flush with anything but the important part is that they are tight against the barrel shoulder. I put mine in with a wrench and remove them with a wrench. Something waxy like bee's wax or Door Ease is much better than a light oily lube. You don't want to make it easy for them to become loose and back out a bit.
