Jm - yes, there is great doubt that a simple bulge will ever open up! Since it has been cold worked (by the gas hammer that made the bulge) it is actually stronger than the surrounding metal. If done with some skill, it can be made to go back in place with only a bit of cosmetic polishing. "Shrinking" is a common sheet metal technique and shotgun tubes are in the same thickness range as sheet metal and of similar composition. The question here should be, "Can it be done economically?", not "Can it be done safely?" If it isn't economical to fix, then he can most likely (affirmative opinion of gunsmith with gun in-hand needed) shoot it as per 2-pipe.
If the bulge has a crease, the we have a differing issue. I'd estimate from the typical published pressure vs displacement data that the pressure in the 15" from muzzle area will range from 1500 to 2000 psi. It would be easy enough to calculate the hoop stress if we had the wall thickness and bore diameter. That will give a good indication of safety factor.
I see no difference in repairing a bulge vs a dent. A dent is only a bulge to the inside.
Last edited by Rocketman; 10/09/07 09:32 AM.
