A Question For Metallurgists

[Joe S]

The barrel pictured below is about four years old. I took it out of the stock yesterday for its annual inspection, and found a nonuniformity that I had not previously seen.  The dark ring area appears as if it might be a channel or area that is below the rest of the surface, but if you increase the magnification, you can see scratches that show that the adjacent areas are contiguous.

So, what is the area of bright metal? I am concerned that it might be an inclusion of some kind that would weaken the barrel.

[Canute Rex]

Hard to tell from just a photo, but here are three possibilities. It could be just some oxidation from surface contact with something on the stock. It could be an irregularity or inclusion from a high concentration of carbon or a bit of debris that got into the original bar casting. It could be a soldered or welded repair of a ding in the barrel. From the scale against the barrel flat it doesn't look very large.

If it were my barrel I would put some 220 sandpaper on a block and take a few passes over it. Then rub it with a little white vinegar or other mild acid to re-oxidize the surface, and let it sit a few hours. If the black ring disappeared uniformly it was an oxidation mark. If the black ring starts to get smaller it's a shallow inclusion. If the black ring stays roughly the same size, it's a deeper inclusion.

[kudu]

I don't want to sound foolish   ( "But I think you have a Sandbur under the saddle") a small piece of dirt, grit whatever. The scratches go every which way longitude and latitude.

 Cant really tell other than the "bolt groove" could have let some dirt in? I assume that's a groove for a bolt or Pin?

[T*O*F]

I've got a pair of Ed Rayl barrels from 20 years ago.  I believe they are 1137.  While finally getting around to draw filing them last week, I noticed similar small inclusions in the steel.  Who made your barrel and what metal is it made from?

[Joe S]

Thanks for your replies gents.

Canute Rex – In hand, the mark looked exactly like solder as you observed. I followed your suggestions to sand, and then oxidize with white vinegar.  The mark is now gone. Whatever it was, it seems to have been a surface phenomenon, and not an actual inclusion. Whew! If it had been an inclusion, I would have probably replaced the barrel. I do not have a clue what may have caused it, but I am much relieved.

kudu – Correct, the groove is for the front lock bolt. I do not finish the bottoms of my barrels, so the scratches are the history of the barrel being made, plus whatever scratches I added during the build. Someone once asked Jerry Huddleston if he polished the bottom flats of his barrels. He replied “No, and I don’t polish the bottoms of my shoes either”.

T*O*F – This is a Bobby Hoyt barrel. I believe it is 12L14. I hope you can get rid of your inclusions as easily as I got rid of mine.

Lightly sanded with 220.




Oxidized with white vinegar