GH Barrel Flat marking
 

I am in the process of cleaning up GH serial number 90291 which is an 1898 Damascus barrel gun ( 30" F, F). I noticed a + mark on each flat adjacent the extractor. I have never seen this before and am wondering what this may indicate any help will be appreciated.

The + stamp is not understood.... says so in TPS. We have seen this stamp on a great many Parker barrel flats.

Thanks, Dean. I am going through some Frontier pads! Actually one, but it's toast!

The barrels have gone from feeling like black gas pipe to slick and smooth so I don't mind the elbow grease. Now that they're clean enough to evaluate I will have them refinished. The more I look, the more I am drawn in by the Damascus pattern!

Joe, My theory is that barrels marked + are bored over nominal. And this alerted the choke boring guy. Check your bores and let us know.

Mr. Suponski have you tested this theory. It seems to make good sense to me. I have a set a barrels marked with the pluses and I could get the bore measured.

Please do Eldon.:)

I am going to have to order that bore gauge! Thanks, everyone!

I have a Gh with out the + gun # 65517 which I think is factory bored over nominal Its a number 1 frame and good wall thickness.

I just measured the bores. Left bore is .731 with .695 at the muzzle. Right bore is .731 with .695 at the muzzle. Minimum barrel wall thickness is .034 Left, .036 right. Isn't .731 fairly normal? Thanks. Joe

Prior to about the S/N range of 60k, the 12ga bore diameter could range from about .745 to .760. I have yet to measure a 12ga bore on later guns that were at the standard of .729. Most seem to be .731 to .735.