My PP idea: 185 gr bullet, SWC if the gun will feed it,, WW air cooled, it will deform in a human and is getting out of the barrel at 1000 fps. The half inch hole should make a good leak and the nickle sized bullet should not exit. I don;'t shoot folks though so this is given based on my NON-infinite wisdom.
Otherwise, just buy a box of Win Silvertips and use those for home protection. That is probably the best advise that will be given and keep you out of jail or at least give you a fighting chance. Search the many discussions on the use of homebrew bullets for PP, attorneys and jail time.
As for the ramp leading, I have never seen any, not after ANY number of dang near pure lead alloys. I figure if the ramp leads, there is some other mechanical aspect that needs attention. I shoot a Kimber and it eats anything. I also shoot an RIA in 38 Super, it eats very little well, vomits at times, but still wont lead the ramp! My LEO friend I load for, same 5 gr RD and 230gr RN load, S&W service model (NICE), eats 500 rounds at a time and it is accurate. (Not bullseye accurate but...), close enough to service load power to give him the feel and POI of ball. No ramp leading.
A 1911 should feed with a reasonably polished ramp, any round nose bullet, if the recoil spring is stock weight. Even pure lead. Ric mentioned feed issues sometimes with the really light recoil springs and loads.