Just got the cylinder back from the gunsmith, and the removal of .004 from the face worked perfectly! B/C gap is about .003, with no binding and good timing on all charge holes. The cylinder ( 449312) will go well with my gun (4K485xx), and I'll test it out this weekend. I kinda feel sorry for the owner of the original gun, but I did check the Forum and the Database for a matching number before proceeding, even though it was on that auction site. The finish on it is less than perfect with one small pit on the breech face and a faded blue that doesn't match the boxed gun, but for under $300 total (including gunsmith and postage), I feel like I came out a winner on this one .


Many thanks to Steelslayer for his suggested solution.