Gentlemen,
I saw on another site where some gunsmiths, including Colt, have re-threaded 3rd Generation barrels to fit 2nd Generation frames. Evidently it works on 24 to 20 tpi, but not the other way around. I tried it on a ruined Ruger Blackhawk barrel, and it worked much better than I expected it to. It screwed right in to my frame, and it appears it would work to re-barrel a shooter. What do you gentlemen think?