Russ-
Poster 458Lott has posted a nice treatise on the buckshot question. You can search for it or perhaps he will see this thread and reply with it. Short answer: don't use buck.
I think it went something like, place a target at 10 paces and unload your baddest charge of 00. If you get a pattern, then you'll realize you're relying on at best one maybe two pellets of stopping or killing a bear. A single pellet of 00 buck weighs a whopping 54 gr, at a blistering 1200 fps that equates to 172 fpe. Let's see what the mighty 380 auto can do. It fires a much more impressive 95 gr bullet at a bit more sedate 950 fps, but wait produces 190 fpe. I'm not a fan of fpe as equating to terminal performance, but it is in this case useful to show how anemic 00 shot is.
So if the argument for buckshot is that aiming isn't as critical as a single projectile, you're trusting your life on perhaps one pellet that has less terminal performance than a 380 acp. I don't know about others, but that falls way shy of what I'd trust to protect myself from a bear.
Hence with the multi projectile theory in the crapper, where it belongs, you should choose a single projectile with sufficient terminal performance to do significant damage. While the 12 ga slug is impressive in diameter and recoil, the terminal performance lags significantly behind a high powered rifle. So with the choice of a single projectile, leave the shotgun for shooting birds, and carry the most powerful rifle you can shoot accurately. And shoot it accurately!
