FWIW, I would spray first, with perhaps a short (18 1/2")barrel shotgun loaded with some sequence of slugs/OO buckshot if in serious bear country. Glad to know that a 357 seems to be effective, because that is what I own.

But really, why this emphasis on bear attacks? Falls and drownings kill many more people, year in and year out, and honey bees regularly off more folks than bears, as does faithful Fido. But Death by Bear is spectacular....