Well, yeah. I've put a .45-70 520 grainer straight through a North American Bison. Would have easily killed one standing behind it as well -- we actually had to wait for a clear shot, not in front of the bison, but behind it. No reason a Cape would be any different. But that was ideal shot placement through the lungs, not a desperate do-or-die shot at the enormous thick skull of something like a Cape Buff charging.