First........where are all you people finding these extra barrels?
Next........actually spoke with Buck today about this very issue. He said most times they won't work. Lefever was the worst of all guns being hand fitted. LC Smith are the most easy to do. That was his exact words(give or take a few). But he said it can be done........on some. Also at times it may take him a number of hours to determine if he can or can't fit extra or new barrels.