A Montana game warden was pinned down by a grizzly they were relocating. He was armed with a S&W M-66 with 158 grain ammo. I was unable to learn just which load.

He fired all six shots in a panic. One hit a vital zone and killed the bear, saving the warden. There were a number of witnesses, inc. a former outdoor magazine editor who wrote it up for publication.

I also know of a case where a man being dragged off by an African lion killed it by stabbing it in the heart. His blade was just six inches long, but worked.