Drew and Joe,
Both of you offer sage advice. Unfortunately I am not in a position to tie it to a tire and test it. Therefore, I will send it to Keith Kearcher and have it honed and ask Keith to measure it after honing. The gun is in the possession of a new Lefever enthusiast who wants to shoot it along with his son at the Uncle Dan Cup in June. I would feel dreadful if there were an adverse outcome. There are always other guns. However, there aren't a whole lot of original Lefevers.

Great-Great Grandson of D.M. Lefever
www.lefevercollectors.com