doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Pitted barrels

How does one evaluate the safety of an old SxS double gun which has several pitts on the inside of both barrels just ahead of the chambers? Rest of the barrel is shiny and appears OK. I know, " have a reliable gunsmith check it" But what does measuring wall thickness tell you? Gun is nitro proofed. Belgian, steel, 12g. with 2 5/8" chambers and from the proofs, was made in the 1900 to 1910 era. I have shot RST low brass shells thru it but now am worried. The pits appear as small black dots. I would welcome opinions!

Measuring wall thickness lets you know if there is enough steel to hold the pressure generated from the shotshell, and yes you should have it checked out. Yes its nitro proofed, but that was in 1900, its now 2018!

Having had a set of damascus barrels honed for removal of pits, and seeing how little he had to remove to get rid off all but one of them completely, I would just have to say you need to rely on the services of Mike Orlen, or someone in his expertise range with barrels. (Maybe Dean at Skeet's in Tahlequah, OK?) He can evaluate them and tell you if he thinks they will clean up with a light hone, then if you want him to he can do them while they're there.

JMO, SRH

But the issue here, aside from wall thickness, is trying to determine how deep the pits are. You may have adequate wall thickness on initial measurement but if you can't get to the bottom of the pits you aren't getting an accurate assessment. Honing the barrels until the pits are gone may leave you with walls that are now too thin.


Edit-saw Stan's response just as I submitted mine.

Scroll down about 1/4 here
https://docs.google.com/document/d/1ZIo0y746UsSRZIgRuuxwAbZjSBHitO_EanvwLYc-kGA/edit

Proper evaluation requires an experienced barrel smith, a high quality bore scope and wall thickness gauge.

Superficial pitting just past the forcing cone is very common (looking toward the breech)



Linear erosions just past the forcing cone are much more worrisome (looking toward the muzzle)



IF the wall thickness is adequate, and an experienced smith believes the pits to be superficial by direct observation with a bore scope, I would not remove metal in the critical proximal 9" of barrel. I have had pits removed further down the barrel and as Stan observed sometimes very little honing is effective.

To be a bit more precise, the barrels I had Orlen hone looked way better than the two photos in Drew's post. I probably wouldn't even consider a set that looked that bad. But, I don't have nearly as much experience in it as some others.

SRH

Dug out a couple more barrel remains. It is hard to get a good image, but the point is that without a quality bore scope, it is impossible to really know what the bore looks like; both looking toward the breech from just past the forcing cones

A bore gauge such as Jon Hosford's is able to get accurate measurements to the bottom of pits.

That depends entirely on the size/taper of the pin, and mostly by feel fortuitously getting the pin in the correct pit, and to the bottom of that pit

Pits in a barrel are like cavities in a tooth.

Damascus barrel pits could even be hidden flaws in the steel that has shown up from years of use and developed into a cavity.

Once rust starts there is no really stopping it...especially inside a small crevice inside of a thin steel tube that's exposed to high pressures, fire, heat, suet then lined with plastic wash and lead.

Pitted barrels are notoriously hard to clean.

Anyone that tells you they can measure the depth of a pit or even evaluate the safeness of shooting a gun with pitted barrels...is to put it mildly full of sheep chit.

You like the gun buy it...shoot it...take your chances.

Only thing you might loose is a finger or an eYe.