Posted by revdocdrew on July 7, 2008, 7:40 pm, in reply to "Bore Size"
William: Hunter Arms increased the 16g bore diameter from .650" to .662" about 1936. 12 and 16g choke constrictions start about 2 1/2" from the muzzle (LRWF chokes may be longer.) The bore at the muzzle for Modified choke should be about .639" and for Full about .629".