That would make a heck of a load. I think a load like that, you better not have a scope on the rifle. That would be a shoulder breaker. Cape buffalo are tuff and dangerous from all I have seen and heard, but would a load like that really be necessary? I would think distance to target would be the big factor. I never hunted anything like that, but I would think within 100 yards and 120 grains of Pyrodex P and a good conical would do the same thing. Or at least hope so...