Going to jump in here for some advice. I just got a 1875 W.C. Scott 12b hammer gun that look in very good cosmetic condition. Ahead of the flats are the three proofmarks and also each barrel is stamped 14. I assume it was a 12 bore proofed at 14 bore.
Using OD-ID/2 I get both barrels with 0.70 wall thickness 9" from the breech and 9" from the muzzle I get .050 (rt) & .040 (left).
The bores are consistent along the barrel, .710 (rt) and .718 (left). The chokes are actually negative, the right barrel opens up .009 and the left opens up .002.
So this tells me that if it was proofed at 14 bore, .693, then the barrels have been honed out .017 (rt) and .025 (left).
thanks,
Rob
Rob, is your gun marked "Not for Ball"? That mark came in with changes made in 1875, so yours might or might not fall into that category. However, if it's one of those, then it should have a mark for the bore followed by a B, like 12B, and another for the muzzle, like 14M. From the measurements you provide, it does sound like a honed out 14, but it's somewhat odd that it's a 12 that started life that far underbored. But if your bore and choke measurements are correct, it couldn't have been 14 at the muzzle because it's way larger than the 14 standard now. Interesting.
