L.C. Smith 10 gauge guns from the early Smith Baker, Syracuse, N.Y. seem to be close to .800 bore. Hunter Arms Co, Fulton, N.Y. 10 gauge bores were listed at .775 and seem to be a +/- .002.
12 gauge from Hunter Arms are .729 again +/- and I have some hammer guns in the .724 bore size. Hammerless seem to be close to .728-9.
Some of these early guns, if you want to call them back bored, but a better term is honed.
I was typing this as Ken Nelson posted his, and I would be concerned with a 12 ga. at .800.
Last edited by JDW; 05/24/13 02:33 PM.