Thanks for providing Robert Hoyt's contact info. I will call him and leave a message, if he cannot answer at the time. My question about loss of barrel length stemmed from a "feeling" that there may be some rifling tool "chatter" near the muzzle and breach end. The breach end would be left as is, and the muzzle shortened beyond the chatter length. But my experience with re-boring and re-rifling is ZERO!