Forgot to mention solids. In my experience, in both my own hunting and the buffalo my hunting partners have killed, solids aren't nearly as effective as expanding bullets, especially in smaller calibers like 9,3 and .375. But have even seen a buffalo shot several times all in the "boiler room," with modern 500-grain flat-nose solids from a .458 Lott that resulted in a long follow-up on a very hot day. The guy was actually hunting elephants instead of buffalo, the reason for only having solids, but they were far less effective than a good "soft" from a smaller cartridge.
