From my reading, it sounds like bears pop their clogs about as easily as deer do, but shot placement is a bit more of an issue because they have thick coats, layers of blubber and very heavy bone structure. I would imagine a bigger bullet/ball helps with all of that, so a 280 grain round ball or a 200 grain 30 cal boolit should be fine. If I am really feeling sporty I suppose I could experiment with the 54 conicals I have on hand. 400 grains of 54 boolit is bound to penetrate really well.