doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Bulge in barrel

I hate to be a spoil sport here But I like to hear from someone who has direct information that a barrel failed due to a bulge particularly if it was 12" or more ahead of the chamber. Lets see some proof that this actually happens.
Jim

I believe this has been brought up regularly. I wonder though, those stress strain charts fall off very rapidly. How can one determine if the bulge stopped on the safe side of the curve.

Maybe, if a bulged area survives the hammer back that's a bit of indication that it's okay? Seems like it's a technique that's regularly mentioned in the old literature. I'd think modern alloys may behave very differently.

The metal may be stronger from work hardening but now it's thinner as well. Would the two issues cancel each other out?

you all know how cheap some folks are...wont take a loss on anything.....makes you wonder how many bulges have bean repaired and the gun sold as if the barrel never was bulged....

Let me walk you through this, Jim. The particular barrel set I mentioned was a Philly 12 ga. Fox. There was a bad bulge in the right barrel about 10-12 inches back from the muzzle (30" barrels). After much time spent putting all the visible part of the bulge back in place, the top rib popped loose from the peening. Since the ribs had to be relaid now, I removed them, and decided to go ahead and remove the portion of the bulge between the barrels. That is when the crack was discovered.

Point here is, if the visible portion of the bulge had been successfully removed without the rib popping loose I would have never known the crack was hiding between the ribs. This could have had disastrous results with ribs flying off from the gas leakage through the crack. Microscopic bore inspection may have found the crack, but how many people have the equipment to do that?

Bulges can and do create stresses in the metal that exceeds the elastic limit. Maybe a very slight ring bulge could be repaired successfully. The trick is determining when the limit has been reached and when it hasn't.

SRH

In the warning Browning issues about not shooting steel in their classic Belgian-made guns (A-5, Superposed, Liege, Double Auto), they refer to the ring bulge that might result as a cosmetic issue. I've often wondered whether a ring bulge might pop the ribs, at which point it goes a good bit beyond "cosmetic". The only reference I can recall seeing about that possibility goes back to the early days of steel, when the wads didn't offer the same degree of protection as they do now. But I still wonder . . . Anyone ever hear of a ring bulge in the choke area popping the ribs??

The A5s had a bit of notoriety for ring bulges well before the days of steel, Larry. The tightly choked guns that were fed a steady diet of bigger pellets of lead shot often had bulged barrels.
I've never seen a rib pop on a bulged gun. That doesn't mean it couldn't happen. One of the regulars here (Don Moody?) astutely pointed out a few years past that pressure would be reduced as the load came to the bulge. Ahlman's Custom Gun has been saying the same thing as Browning for years, it is a cosmetic issue when the bulge is at the muzzle.
It would bug me if a good double had a bulge, however.

Best,
Ted

May and should are scary words when considering the close proximity to hands and eyes!

There was a KED-Grade Remington hammerless Double that my Father owned, and then passed on to his younger brother when he returned from WW-II. That gun survived decades of use with all manner of smokeless powder loads including plenty of Western Super-X and Federal Hi-Powers. In the early days of steel shot some of my cousins were shooting it goose hunting out in Western Minnesota, bulged the chokes and popped the ribs loose.

I've examined two of the quite rare Ithaca NID Magnum-Twelves with bulges at the start of the choke area, but neither had yet popped the ribs.

Stan:
You make an excellent point in your above post regarding hidden damage. After discovering this I would have strong reservations about continued use of this gun.
I also remember reading,and I believe it was here, regarding owners of damascus barreled guns finding minute holes right through their barrels due to inclusions that were present from the original forging process. I think they had been shooting these guns for years without ill effects.
I also have a friend who continued using a Winchester Model 12 after it was discovered to have a bulge in the barrel at about the halfway point. He used this gun that way for years and in fact may still be using it.
I know it's not a shotgun but I continued shooting a Colt OMM for quite some time with a barrel bulge until I finally located a replacement barrel.
As an aside: I suspect it would be interesting to run some strength tests with bulged barrels much as was done with damascus barrels.
Jim