Bill;
Choke cannot be determined by muzzle measurement only, it needs bore dia as well. From a nominal 10ga bore of .775" these would have .025"/.030" constriction which in a 10ga would be strong modified to imp-modified. "Many" Lefevers however were bored oversized for use with brass hulls. Lefever referred to the rib design as "Engine Turned" & was standard for them. Some early 10ga guns had 2 5/8" chambers, but 2 7/8" dates back very early as well. Guns were also available on special order with different lengths of chambers. I have a Lefever E grade 10ga SN 10,515 with 3" chambers. I of course cannot prove it was not rechambered, but to my knowledge 3" has never been a standard chamber length for the 10ga in this country. Chamber length is measured per the "Fired" shell length, a longer shell will enter the chamber because of it's shorter crimped length. I hope he was not firing the 3½" Magnum 10ga loads from it. Engraving looks more like the D to me, certainly not that of a B grade. As I mentioned over on the Lefever board this gun was built out of sequence for the serial number. It is quite possible the frame had stayed in stock & it was finished up from parts after the Co was acquired by Ithaca. Perhaps it was built as a D grade but a set of B grade bbls were fit up to it. Hopefully others can add more insight to this gun. It should definitely be worth some restoration effort. Buck Hamlin would be a good man to contact, probably someone here can give you his contact info, he is a specialist on Lefevers.
