Have two sporters in the family, one with a pristine bore (24 in barrel) the other with pitting in the grooves from chamber to muzzle (20 in barrel). Both have Redfield no-drill peep sights and shoot extremely well with cast, the pristine best with the Lyman 311291 and the pitted with the Lyman 311284. Bores mike out a shade under .309 and we are sizing at .310.