....In the case of a movable obstruction the burst may actually come forward of where the obstruction initially was, the amount dependant upon the resistance of the obstruction. Another thing to consider also is that at this point in the barrel the inner wall is supported by the other barrel, the point to where they become separated has not been reached. Consequently I do not see it as unusual the bulge was confined to the outer wall.
I seems to be possible. I think I can see machining, honing?, marks just opposite the bulge, they appear crisp and unaffected by the pressure it might have taken to the blowout in the other direction. It seems like in the chamber maybe about mid hull the scratch pattern is smooth and it seems like the measurements say the chamber may be bulged back by the case head.
I wonder if the pressure spike was actually in the chamber and too high, or built at too quick a rate, for the metal to deform. Maybe at the bulge the pressure was dropping to allow the metal to act in a plastic way. I think the picture of the monosteel blowout in part 2 on Feb. the 5th. shows similar, but may also be more of a 360* bulge.
Thanks again Doc Drew for digging deeper. Maybe back to the reloads you took apart, you could tell something about the depth of crimp or possible primer substitution. Could be a moving obstruction from a load that pressure spiked and the old Remington just had enough of. I've wonder if Tony T's barrel crack right out of proof would have looked similar if someone had put a few more rounds through it.
