A question for those of you who actually do this for a living:

In a buffalo or elephant charge, how close do you let the animal get before firing at the brain? Of course, individual ability and situation will be determining factors, but if YOU have a big nasty coming at you, when do you fire? Assuming an adequate calibre, of course.

I have been meaning to ask this for years, but a crabby elephant brought it to mind (or brain) again yesterday. He changed his mind before I had to answer it for myself.