cybersnow,, you started asking about the Redhawk. Not a Blackhawk. They are two very different revolvers. In how they operate, how they feel, & how they are fed ammo. Only YOUR hands can determine if they fit you or not.
BUT,, to answer your question,, a Ruger Blackhawk, in .45 Colt/.45 acp,,can & will shoot "Bear Loads" easily. But since you didn't specify WHAT kind of bear loads,, I'm assuming you mean some factory offerings.
I load my own,, using a .45 Colt, with a MP molds cast 280 grn bullet,, running a tad under 1200 fps. I carry that bear hunting here in WNC,, where a 500 lb bear is not uncommon.