I like the M-14 idea, M1 is nice as well... $$$$ I guess.
Unfortunately, the only rifles I have now are XR-15 and 10-22, neither of which I want to tangle with angry black bear.
In a real pinch, how well would a .45 with PMC Starfire SFHP do? That's what I have loaded in my usual carry gun, which is the most accesible (as in always loaded, not in a safe)