Crusader

You are correct, most countries and provinces require a .375 or above for cape buffalo, elephant, rhino. Lion and leopard are often different, and have lesser requirements. Some South African provinces allow a 9.3mm. Namibia has an energy requirement. Its listed on more than a few posts on NE.

A 9.3x74R will kill a cape buffalo fine. I know some people who have used it. I haven't on cape buffalo but have shot fourteen water buffalo with it. Water buffalo are slightly harder to kill than cape buffalo, IMO, but less aggressive, per some people's comments which is probably true.