Not quite on point, but I once destroyed a Colonial aftermarket Improved Modified tube in an old 12 ga 3" Citori, shooting steel T-shot at snow geese. It seems that the shot hammered the tube into the barrel threads, and it took a capable gunsmith to get the tube out. The tube was a total loss, but the barrel and its threads were fine. No bulging of the barrel. Gun is probably early 70's manufacture, still use it on ducks.