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rpm
PostPosted: Wed Jun 28, 2006 7:55 pm  Reply with quote



Joined: 25 Jun 2005
Posts: 50
Location: CO

A few months ago I purchased a '61 12 bore Superposed. In both tubes, about a shell's length forward the forcing cones is some light pitting - at first I thought it was fouling but after a vigorous brass brushing it remained. It is not deep but it does cover the circumference of the bore at his point. Any danger in shooting it like this? Obviously what's done is done and I don't think back boring or even lengthening the forcing cones is a viable option w/ the thin Superposed barrels. Your thought are appreciated.
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16gaugeguy
PostPosted: Thu Jun 29, 2006 5:08 am  Reply with quote
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Joined: 12 Mar 2005
Posts: 6535
Location: massachusetts

If the pitting is not too deep, it can be polished out with crocus cloth followed by steel wool. This can be done with a hand drill and a 3/8 dia. metal rod slotted to hold a small piece of crocus cloth and a short length of inner tube as a buffer. Wrap the rubber patch and crocus cloth on so the rotation is in the right direction so the patch tightens around the rod as the drill spins it. You will need to add or subtract some of the patch to get the right fit at first. The patch should be just snug and not very tight. Twist the patch past the chamber and forcing cone by hand. If you can't do this, the patch is too tight. adjust it. a little trial and error will get you there. Then roto polish the bad spots. Use a light grade motor oil as an agent to let a slurry of grit and polishing fines form. The process will get rid of any shallow pitting in about 15 to 30 minutes of intermmitant polishing. Keep checking your progress and stop when all the pits are gone. You might have to use several patches of crocus cloth. Wrapping a 12 ga brush with OO then OOOO steel wool and running it up the bore after the polishing will finish the bore to a nice high sheen. you can use the front end section of an old cleaning rod for this.

I've done several guns like this and it gets rid of shallow pitting like a charm. I also regularly roto polish my target shotgun barrels with OOOO steel wool about 2 to 3 times a year. Each time I do it, the bores get better and I get less fouling. The bores are also very much easier to clean. I've also noticed a slight decrease in felt recoil over the last few years. OOOO steel wool does not remove any appreciable barrel steel, but helps clean and polish the bores like mirrors. This helps all modern guns shoot better with one piece plastic wads. Just don't do this to old vintage guns.

If the crocus cloth lapping does not help, taking one or two thousandths out might. A light reaming that only goes up far enough to get rid of the pitting will not hurt a thing. As far as lengthened cones, I've seen hundreds of Superposed guns with lengthened cones. It will not hurt the gun if you don't opt for a super long cone. Have someone reputable do the work. Make sure he polishes the bore well after. That step is often overlooked or done poorly. Make sure your man does it right.

The pitting will cause a problem with plastic and fouling build up at this spot and the stuff can be very tough to remove. If the pitting is close enough to the chambers so lengthened cone removes it, I'd choose that option. The gun will shoot better and with less felt recoil. A good shotgun barrel smith will know what is right for your gun.
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