doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Barrel bulge

Does anyone know of anything that would cause a barrel bulge about 18" in front of the chamber except a bore obstruction?

cleaning solution or oil not patched out?

jack

Low probability, but shot bridging could do it.

Shot "leaking" from a cartridge before firing.

Would that not be a type of barrel obstruction, Daryl?

Of course shot leaking would be an unexpected or unnoticed obstruction type. Not in the same way a stuck wad, snow, or other barrel obstruction by a foreign source that could be seen "before" putting the shell in the chamber. I guess if one takes your line of thought, excess oil or cleaning fluid would be an obstruction, too. But since the problem of a leaking shell or shot bridging, as you say, could not be seen prior to loading and firing, I would consider them similarly. Each causes an obstruction at some point.

If barrel wall thickness is adequate, it just about has to be an obstruction in the barrel of some sort. Retained patch? Who knows? Another lesson: chec your barrels very very frequently!!!

My guess would be that a bulge at 18" has an Ivory Soap percentile (99.98% Pure) chance of being an obstruction. I have seen some reports, which appeared to be verified, of a bulge or burst occuring from a phenonimum of the shot charge itself acting as an obstruction. This occured from incomplete combustion of the powder charge getting the shot a ways down the bore & then the burn increasing & the gases rushing down to catch up with the slow moving shot which created the obstruction. This can occur with the first shot from a verified clean, unobstructed bore. Some feel this may well have been a problem with the early smokeless powders which didn't ignite as easiy as had black, but were often loaded using the same primers. Smokeless powder in Damascus of course received the entire blame.
This is one of the reasons I am not a proponent of very low pressure loads utilizing slow powders behind light shot loads.
This however would normally occur much closer to the breech than 18", so I would still opine an obstruction.

Shooting BOOMERS in a gun not proofed for boomers????

These were sabot's shot through a new rifled barrel. The barrel was proofed. I have had a couple of reports all with the same mfg of shells. And the reports was that it was not the first shot in the session, could a piece of the sabot from the previous shot be left behind?