barrel bulge question

[atr]

Hi guys
I have a 12 GA 2-3/4" dbl barrel shotgun. Ithaca but manufactured by SKB in Japan. Really nice quality BUT there is a slight bulge in the Modified side of the barrel. The barrel is 28" long and that bulge is 12" up from the receiver. My question: Will that bulge significantly affect, or in any way affect the pattern?
thanks
atr

[recumbent]

I doubt it but the only way to know for sure is to go out and pattern it

[Winger Ed.]

I'd guess 'probably'.

As the pellets spread out in the bulge, and then compress back down in that short space on their way out,
I'd think enough of them would get flat spots for the pattern to spread out more than normal.

[Longknife]

Have you ever heard of a Jug Choke? A jug choke is usually done to muzzle loaders. It is a process of reaming out the bore an inch or so from the muzzle. This enlarged choke lets the shot expand into the jug and then it is compressed when it passes through the choke in the last inch or so of the barrel. I have had great success in jug choking barrels that produce excellent patterns with out damage to the shot. The Jug measures in imp, .008 , mod .016 and full .024. This choke lets you use near bore size round ball with out affecting accuracy. I dont think the bulge would affect your shot but I would be concerned that the barrel has been weakened by the streaching of the the metal....LK

[Hdskip]

I'm with longknife I'd be more concerned with weak spot in the barrel.

[recumbent]

How did the bulge get there???

[SuperBlazingSabots]

Greetings, what happens when you get a crack in your windshield, when you keep driving ?
You barrel must not be very strong to start with and by now even weaker and ready to blow up !
Bulge is 12" up from the receiver, can't even cut it off before the bulge.


Ajay K. Madan
Super Blazing Sabots

[243winxb]

The plastic wad may not seal in the bulged area. Gas blow by. Poor pattern? I would not shoot it.

[GregLaROCHE]

I would get a good gunsmith’s opinion as to the safety of using that barrel. You may not notice anything right away, but stress fatigue could cause it to let go in the future. Do you know what caused the bulge?

[Cap'n Morgan]

I wouldn't worry too much. At 12" the pressure is less than 2000 psi - about 20% of the chamber pressure. As for the pattern, it may open up a tiny bit due to shot deforming, but you'll not be able to tell the difference (and most shotgunners use too much choke anyway) The bulge was probably caused by an obstruction left in the barrel, most likely a wad.

[atr]

it was NOT the quality of the barrel that was at fault. I screwed up. I used a friends reload, it went bang but did not push all the wad out. I put another round in and that is when the bulge formed. The second shot trying to push out remains of a previous shot.
The bulge itself is not very large.


The bulge was probably caused by an obstruction left in the barrel, most likely a wad.

exactly what happened!

thanks guys

[dverna]

Put up a large piece of paper and pattern it. I expect you will not be able to detect any affect.

I would shoot it if it patterns OK.

[longbow]

I'd like to see an answer from a gunsmith.

I have seen expandable devices for removing dents from shotgun barrels and have read that it is okay to remove dents but not recommended to remove bulges. Not really sure why as both are plastic deformation of the steel, meaning the steel has yielded. If a bulge is small I can't quite see why it can't be hammered or pressed back down onto a bore filling mandrel to remove it, or at least reduce it dramatically.

If its a big bulge I'd tend to be concerned in that a large area of metal has yielded and stretched so likely not a good idea to repair it. However, as Cap'n Morgan points out, if the bulge is up the barrel a ways then pressure is much reduced so repairing or even leaving the bulge may not be an issue. But that is speculation on my part. I'd like a gunsmith to comment or someone who has had a barrel repaired... or repair rejected by a gunsmith.

This seems to be a frequent topic but I have bot seen a definitive answer on this forum or others.

Longbow

[atr]

I am going to pattern it...and I will let you know what I find.

The idea of using a mandrel is intriguing.

[Der Gebirgsjager]

There are two ways to correct the bulge that I am aware of. First one is a tool sold by Brownell's. Right up front--it's expensive. It works like the old time shoe spreaders worked--but you younger folks have never seen one. You insert the tool into the barrel and twist the handle until the two parts of the plug on the end of the handle spread apart tightly against the inside wall of the barrel. Then you tap the exterior of the barrel with a suitable hammer until it flattens down against the internal plug. Hard to do this without some marring to the exterior of the barrel, because non-marring hammers like plastic, rawhide, and wood won't do the job, so you need steel or brass. If the gunsmith then refinishes the exterior of the barrel you'll never know it was bulged. The tool is quite expensive, and not used that often, so most gunsmiths never buy one. The second method is to carefully measure the internal taper of the bore and machine a mandrel on your lathe. Drop it in, and then once again tap the metal back down into place on the mandrel. I used this method quite successfully on several bulges.

DG

[longbow]

Brass or bronze hammer shouldn't mar the barrel but bluing might suffer some. Bronze is harder and should do a decent job.

Any idea of how big a bulge is too big to fix?

Longbow

[Duckiller]

I shot trap and skeet with a gentleman that bulged the barrel of a Citori in the same way. He decided that the price of repair that he was quoted was too much. He continued to shoot it with the bulge. Did not effect his scores,AA shooter.

[Geezer in NH]

Greetings, what happens when you get a crack in your windshield, when you keep driving ?
You barrel must not be very strong to start with and by now even weaker and ready to blow up !
Bulge is 12" up from the receiver, can't even cut it off before the bulge.


Ajay K. Madan
Super Blazing SabotsWrong, needs a form 1 filed with the ATF and 200 dollar tax when approved cut away!

[atr]

OK guys...I took the 12 ga out to check the pattern.
The first round was a Alcan manuf. (old stock) #8 shot 1-1/8 oz. I set the 24"x30" paper target at 30yds.
the pattern was good, dense, no gaps. The picture is too big to up-load, take my word the pattern looked good.

The second round was a handload. #6 shot a little over 1-1/8 oz. Paper cases, (1) 0.135 over the powder nitro card then a #6 Alcan Flight-max and 18 gr of Hi-Skor 700X. Again the shot pattern was consistent and dense.

Let me tell you about the hand load. I have saved all my old reloading equipment from the mid 60's. The press is a Herter's, and I have lots of paper cases which I have saved. I haven't loaded shotgun since the mid to late 60's so it was a re-learning experience. I finally got the hang of it and produced some decent loads. Lots of fun getting that old equipment back on line.
ATR

[W.R.Buchanan]

Maybe a picture of the barrel so we can see just how "bulged" the barrel is?

How long is the bulge, and how big in dia it is. Has it separated the barrel tube from the Rib?

These are all questions I had.

Randy

[Cap'n Morgan]

I once read of a guy who had his German drilling run over by a milk wagon (back when they were horse-drawn and had steel rimmed wheels) Both the Boehler Blitz shot barrels were flattened, but a gunsmith managed to repair them to a state where you couldn't tell they had been damaged.

I once did a, mostly cosmetic, repair of a Simpson Suhl which had developed a bulge just behind the choke. I used the metode Gebirgsjäger describes, using an internal plug and an ordinary peen hammer (flat side, of course) The repair was still visible, as the barrel had some spring-back, and the part of the barrel under the ribs still had a bulge, but the owner was happy with the result.

[Win94ae]

It may pattern like a banana! :/