I'm sure a .50 cal bullet of most any type at 25 yards placed right will dispatch a black bear effectively. I don't know that they are any tougher than any other big game of similar size. Just the fact they havecanine teeth and claws that makes it different from our perspective.

I hunted them with a muzzleloader a few years ago here in CO, ended up in thick oak brush patch about 20 yards from a cinammon colored bear feeding on acorns. I'd see his paws reach up and pull down the oak brush to get the acorns and could hear him chomping away, and wouldget aview of his (her?) head once in a while. Huge adrenaline rush at first, then it drug on for probably 10 minutes or so andI settled down enoughto probably have made asteady shot. The game ended with us eye to eye at about 15 yards, at which point hevanished instantly, no time for a shot. Didn't need to shoot at that point anyway, plenty of thrillshad been had.

I was using a .54 cal with great plains bullets, had no worriesaboutdroppinga bear if I did my part. Good luck!