I have a dentist friend from the Atlanta, Georgia area who has killed 13 cape buffalo bulls with his own handloads with 250 grain Barnes X bullets in the 9.3x62 mostly one shot kills and all were drama free. He has also used a RWS bullet in the same cartridge with good results on a few bulls.
The 250 grain TSX in the 9.3 will out penetrate the various 286 grain lead core bullets.
My own Steyr SM 12 uses 250 grain TSX bullets that chronograph 2700 fps.
The difference between full power loads in the 9.3x62 and the classic 375 H&H loads is conversational on game up to the size of cape buffalo. For a noticeable increase in power, one must step up to a 416.