I don't know about cape buff - but a cast flat nose WW bullet will work wonders on a big bear. They will expand and still drive deeply - lengthwise, if that's what you want.

The late, great Elmer Keith once advised me to use the 560gr. Lyman flat nose for cape buffalo from my .458, driven at around 2,050fps. I am sure it would have done the job. One merely hardens them to act as solids, or leaves them as-cast for some expansion.

Woodleigh must make jacketed softs for the .500's.