I'm not a big revolver guy ,but I think you have to really watch out for bullets without a canalure. They have a tendency to pull out of the case from recoil.
It is something to watch for.
I would go with lead bullet and if your going to order them get them from
http://powdervalleyinc.com/ and look under cast section for Missouri Bullet Co. They make several 240gr and a 300gr TCFP(which would be good bear medicine). I personally like to go heavier, for the mass, in areas of stopping something.