Why on earth would you want to do that to a very collectible rifle, especially if the bore and chamber is good and rifle is complete. i haver and shoot a 297/230 Morris in a francotte and it shoot quite well. It requires some investment but put in shooting order, but the effort is well worth it,

Surely you can find some bubba'd rifle down there that you work with.

The 45 Colt is consider too large for the little Francotte and BSA action. The barrel tenon is to small and the walls of the chamber will be to thin and can bulge.