Possible barrel bulge

[Mills Morrison]

I have a GH 12 gauge. When I look down the left barrel, there appears to be a shadowy area beyond the chamber which looks too clean to be pitting. On the outside of the barrels, however, there is no sign of any expansion. These are no. 2 frame 12 gauge barrels and are thick as culverts. I was just wondering if a bulge would show up inside the barrel but not outside or what this imperfection could be?

[Rick Losey]

frosted or maybe rippeling ??

[Jerry Harlow]

Chambers recut out to 2 3/4" will appear that way. Not clean as when they are originally cut by the factory. Just my guess as I have several with that appearance. But is yours not done in the right side as well? Maybe someone only opened one side and quit for whatever reason?

[Chuck Bishop]

Are you describing the forcing cone? It's the transition between the chamber and the bore.

[Mills Morrison]

Thanks for the responses.

[John Campbell]

Mills:
It certainly IS possible to have a "bulge" or ring inside the barrel that does not manifest itself on the outside. I've seen it more than once. The steel merely compresses on itself.

But from what you describe it should not effect your shooting. If a ring is what it is.

[Mills Morrison]

Well I checked them again and this time felt up and down the barrels and it is a bulge. There is a small bump which you can feel, but cannot see. :crying:

The upside is this was a rescue gun to start off with and it looks like I will just need another set of barrels for it.

[John Campbell]

Mills:
As I said, the flaw will NOT effect the way the gun shoots. Only you will probably know it's there. But if you can't live with it, send the barrels to Kirk Merrington and have him take the bulge out. It will be WAY cheaper then new barrels fitted up.

[Mills Morrison]

Thanks John. I will probably use this as an excuse to stop by Darlington Gun Works on the way to Sanford.

[Dennis V. Nix]

I am curious. If there really is a bulge there won't the barrel wall thickness be thinner in that area? If so isn't that where most of the pressure is generated, right near the forcing cone? Again I am not disagreeing but am curious.

[Mills Morrison]

Whenever there is any reasonable doubt, I get an expert to check it out. I am no expert for sure.

[edgarspencer]

Mills, Don't write the barrels off if there is a slight bulged at the forcing cone. I have gun I was lucky with, which had precisely the same bulge, and I was able to 'tap it back down using a piece of think brass stock (.5" x 1") and a small ball peen hammer. I slowly worked the bulge right back to where the barrels were when they left the factory. I did make a mandrel to insert in the bore before I began.

[Dean Romig]

Be sure to look very closely at the brazed joint line betheen the lug block and the barrel flats. If it is truly a ring bulge at the forcing cones caused by a cartridge that was either too long or too powerful for the chamber it may have split that brazed joint.

[edgarspencer]

Not to say that couldn't happen, but a bulge from excessive pressure is more likely to happen at the weakest point, which is the farthest from the strongest point. The silver soldered, or brazed locking lugs ads mechanical strength to that portion of the barrel, so a bulge isn't as likely to occur there , as it is more distant from the lug. You seen plenty of those aneurisms down near the muzzle, and they are most frequently off to the sides, directly away from the ribs.

If it weren't for companies like RST, I don't know if I'd be as willing to shoot my previously bulged gun (despite the fact that it too was visually undetectable).
When metal stretches below a point refereed to it's YIELD point, it relaxes to it's original size or shape. When it stretches beyond the yield point, it no longer relaxes, and any additional stresses, in theory, only cause additional elongation. There's a fine balance in selecting steels. As strengths go up, ductility generally goes down.
Sherman Bell's backyard test-to-destruction was one of the best reads I ever had. Even the non shooters in the physical testing lab wanted to duplicate it. I had plenty of visits to Aberdeen proving grounds, and they could all be summed up by "HOLYSHIT"

[Mills Morrison]

It looks like it was just beyond the chamber and about at 10 or 11 o'clock on the left barrel. This is a no. 2 frame and the barrel is real thick on the chamber end.

[charlie cleveland]

mills if you can not feel or see a bulge on the out side of barrels i dont think you have a bulge.... charlie

[Richard Flanders]

If there's plenty of wall thickness I'd take the bulge out and keep on shooting it. If you get to watch someone take it out you'll be pleasantly surprised at how easy it is to do a good job with the proper tools. If you refrain from putting the old 1-1/2oz magnum duck loads through it you'll likely be just fine. Just be smarter than the last guy was with what you put in it.

[John Dallas]

If there is no evidence on the outside, how can it be called a bulge? If the metal yielded for some reason, resulting in a spooned out section on the interior, where did the spooned out material go? Should result in a ridge surrounding the spooned out area. Is it possible the bad area was honed for some reason?

[edgarspencer]

a slight bulge can be visible looking down the bore, and certainly measurable. but only barely perceptible to the touch, but not to the eye on the outside.

[Mills Morrison]

The bulge is perceptible to the touch, but not to the eye. I am going to have an expert look at it. If no danger, I will probably leave as is and use RST with it.

Thanks for all of the responses :bowdown:

[Jeff Christie]

I have a little 1 frame PH 12 ga with twist barrels I picked up in a trade. It has a small bulge just ahead of the forcing cone at about the 10 o'clock position in the left barrel. I didn't notice it when the trade was in progress (I am glad I didn't or I might have not gone through with the deal). It is barely perceptible to the touch or the eye. I use light loads and don't worry about it. It is just a fun little gun to shoot and it hammers roosters. It is my oldest Parker yet has dimensions that are very close to 'modern' and is very shootable. That may be because it has a Parker replacement stock from the Twenties.

[Mills Morrison]

Jeff, That sounds like my situation. The bulge is right at the 10 o'clock position and I actually bought this gun for Julia and we have both shot it, although she has lost interest in it. All the responses here make me feel a whole lot better about it.