doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Small bulge 5" from standing breech - any ideas?

joe: if the gun has special meaning to you, then perhaps an investment in a pair of briley 20 ga side kick tubes is in order?

Thanking you Chuck for the infor. and others for your opinions. OD of left barrel is .915 inch opposite where the partial bulge is on right barrel. Bore is .727 inch. I am thinking to ask a friend in the grinding business to make a reamer to ream just past the bulge and taper into bore over a few inches of run. And will strike off the bulge on the OD of barrel. Surely I will proof test and take before and after measurements to see ikf the barrel is expanding when fired. I will report here once that is done.

Joe,
A "taper pin" reamer that has a 1/4" per foot taper will leave a 4" long forcing cone. Before you use it, you must confirm that the taper of the outside of the barrel is less than 1/4" per foot to ensure you don't have a spot thinner than the current corner of the chamber. I believe a Fox has a taper less than 1/4" per foot on the outside. If so, you'll be fine.

Have you given any thought to forming the bulge down using a plug before filing?

Chuck H yes I have thought of using #11 taper pin reamer. Bulge is centered about 2 inches in front of chamber. Forward end of bulge probably has to be opened to .750 inch diameter. Doing the math the taper pin reamer will open front of chamber to about .795 inch diameter,just a hair under the max sizing. That m ay be better than getting a custom reamer done up by friend but I still need to look atb the math to include back end of chamber to see if reamer will clear that diametger. I also thought of forming the bulge down on a bore plug before reaming but I don't want to loosen thebarrel ribs.

" My Skeets shows the bulge is .017 above bore diameter but that's only on one side. Bore probably has to be opened at least twice that to clean up the ring bulge.? Ideas please."

In one word RUN.

First question is why did it buldge in the first place? Obstruction or metal defect? Then how much metal are you looking to remove? So are you saying that you will need to remove .034 from the bore to clean it up? Or are you thinking .017 inside and .017 on the outside to bring it down flush? Or even more scary .034 inside and .017 from the outside. That would be a total of .051. Have you measured the barrel in this area? What is it .094 or less? If so are you going to take .017, .034 or .051 any of the three would be too much to remove in this area. This is near the area of highest pressure not out near the muzzle where pressures are much lower.

In every combination I would say forget about it. The metal has already been deformed and you are talking about removing more metal. Why to remove the blemish or to make it stronger? No. Removing metal will only make it more cosmetic not stronger. I know that the numbers might say failure is not likely but numbers would have said the first bulge was unlikely as well.

Worse is location that is between the face and your hand. If it blows you probably will not loose a finger or an eye but then again you might. Worse what if you die and one of your grand kids inherits grandpas nice Sterlingworth. Isn't that a nice legacy for him to inherit? Bores look clean, barrels show no bulges but unknown to him is the very thin area right by his face. Drop in two heavy loads with pressure to loosen your fillings and hope his and your luck holds and the barrels as well.

Why take this type of risk on a gun that on a good day might top a grand? If you want to keep it shooting find and fit a new set of barrels to the gun. I would strongly recomend not trying to save this set short of a sleeving job.

I'm not sure I understand. If metal is removed then it's safe? Why not just shoot it as is. You could shoot a proof load with the current bulge and measure for differences. I'd still wonder why there was a concern in the first place.

I agree with Chuck's metalurgy. Looks to me like you will be removing .034" diameter on the inside and 0.034" diameter metal on the outside; meaning you will remove 0.068" of wall thickness. And, it looks to me like you have 0.094" (0.915" - 0.727" = 0.094") total thickness which means you have 0.047" walls (0.094" / 2). Obviously, removing 0.068" from 0.047" doesn't work. Guys, I will be first to say, "Check my math - I have been known to make nisteaks."

I doubt a metal defect for cause of a ring bulge. I'd bet on an obstruction. I'd also bet on the bulge not growing or failing. BUT, I'D INSIST ON A CHECK UP BY A BARREL MAN!!!!

Joe
Send me the barrels and I'll do my best to minimize metal removal. I'll return them in the white.

R'Man;
I find it extremely hard to believe you did this. Obviously 0.915"-0.727" = 0.188" which assuming symentry = 0.094" ""Wall"". Also as the bulge measures .017" the .034" is going to be on the Diameter, you need .017 off the wall both inside & out so actual wall reduction is going to be 0.034" not 0.078". Remaining wall would thus be 0.060". Personally I would think it more advisable to shoot as is rather than taking even this much metal off it.

Forming .090 thick steel is not much more of a challenge than the thinner areas of the barrel. Barrel steel is malleable beyond most people's understanding.

I would not recommend simply removing metal from both surfaces as the fix. My approach would be to put as much metal back into shape as possible first to minimize metal removal.

And Joe, I have a taper pin reamer already ground for a 12ga chamber and you're welcome to use it, but I'd avoid using it for this fix as I believe it can be done with more finesse than just cutting and filing metal.

Another thought, I'd get a wall thickness gauge on that specific area to validate that the wall thickness is adequate before proceding. It's suspicious that the bulge is on only one side.