I do not agree with just shooting a bear because you feel afraid. Give the bear ample opportunity to move off, make every reasonable effort to scare it away( yell, throw rocks, pepper spray him, whatever). Last Resort...shoot him but not with that 45acp. Don't give up your high power for a 45ACP. High power for a 454 Casull or a 12ga with slugs, yes. Hang the quarters up in a tree, those black bears will climb to get them, so rig up a make shift meat pole between two trees. Carry marking tape and flag your way out, just make sure you take those tags down on your way out of the woods with your meat. Go prepared for an overnighter. People think I am crazy but I carry a small daypack with a survival kit, first aid kit, some extra food and water, and a tarp for a make shift shelter. I carry it no matter what. 1 mile from the road or 10, it is on my back. If you can't afford a GPS( which don't work real well in downfall timber) get yourself some maps and some compass training. Pull out your compass, take a heading and add 180 to find your back azimuth.
Just remember you are in the wild and intruding into the bears home, not the other way around.