I've had to deal with two charges. First was a buffalo which was poorly shot and waited for us as we tracked. One shot from the PH's .458 WM turned it, by which time I managed to get one in its rear end, but my shot was useless.
Second was a leopard. First time it charged was from about 10 feet, and three shots from a Remington semi-auto 12 gauge turned it but didn't kill it. We knew where it was hiding, and got a tracker to throw a log into the bush. When it came out three of us who were armed were ready (and two trackers holding flashlights). It took a shotgun round (buckshot), a .300 WM and a .458 Lott. Dead. Skin was a mess but no one hurt.
The ability to get off multiple shots quickly is under-rated. Apart from lack of practice, the problem hunters face is that a scope is not only useless in a charge, it's an actual hindrance. A good reason for detachable scopes. Take it off for follow up on dangerous game. Which means it might be useful (and a bit of fun) to practice closer shots on moving targets without a scope.
Realistically though, these are issues for the PH rather than the hunter. Having said that, I was glad I was at least able to hold my own in these situations, and if you're going to hunt dangerous game with any regularity, it's worthwhile practicing and making sure you have the right equipment. I would like to think that anyone hunting dangerous game could do what
@Philip Glass was able to do, but I know that's not the case.