Could it be that a 45-120 can be loaded to 45-70 performance at lower pressures? It seems logical. I have never tried that. I have owned several 45-70s and they seem to be a good idea in a double. Anything in North America with a double tap. There are reasons the Bison almost disappeared. 45-70 was one of them. And at BP velocities! I think a 45-70 in one barrel and the 12ga with slug beside it sounds workable. Back to the Cape gun. Keep on kickin'. Rustyzipper