Gbro on the right track. Your eyes, ears and noggin are your best bear weapons. The pistol is for when things go wrong. I don't worry so much about rogue bears, as I do rampant men.
A hardcast .44 SWC penetrates all out of proportion to its size. I just read somewhere that in a gelatin block test that .44 hardcasts were penetrating the length of the test blocks and not being recovered. Expanding rifle bullets, in common calibers, were stopping with room to spare. Ol' Elmer was telling us that years ago.
A 7.5 Blackhawk is a pretty big pistol. I'd load'em to average velocities and sally forth.
No bears here, but I've been in some NW bear country when I couldn't be armed and would have much welcomed your Ruger!