Lions and buffalo are amazingly quick and it has been my experience that you don't get an opportunity for a quick follow up shot with a handgun. Sometimes you don't with a rifle either. Here is the thing about buffalo, unless you find one that is a single animal, you damn sure don't want to hit your buff on the first shot and then wound another one in the fusillade that follows with "quick" follow up shots. Like someone once said, "if your first shot on a buffalo isn't fatal then the next 27 with a big-bore rifle will have little effect". That's obviously an exaggeration but I think everyone gets the point.