I just got some 300grn jacketed flat points for my .454, seem to be some good ones, I had been using 335 grn hard casts, but I don't think a bear would tell the difference, casts slow in the barrel a little bit. Still have some 335's, and would still use them. I just found some 320grn casts for my .44mag, which I'm gonna use, was using 280 grn jfp. If you are looking into bears, 300 is a good place to be, don't go too much less, but you won't gain a lot for going too much more.