Here is my take...

A firearm can serve two possible purposes: protection and food gathering.

The prime key of a defensive firearm is that it is ready when you need it. This means having it on you or nearby. To me, a handgun on the hip would be ideal for this. It can be plenty accurate up to 25 yards with a little training, and passable at 50 yards with more training. If something is more than 50 yards away, it can't hurt you (assuming threats with 4 legs).

For putting food on the table, a single-shot would be fine with me. If you know what you are doing then one shot should be all that you need. A single-shot will also be more reliable, simpler to maintain, and lighter. It is also cheaper, so you could get two -- one for the truck and one for the BOB, or one to practice with and one for the BOB.

Plus, all it took was one shot for Jed to discover the oil on his property and move to Beverly Hills. <img src="/images/graemlins/tongue.gif" alt="" />

Of course, if you are limiting yourself to one firearm only, I would want something that can fire a 2nd shot fairly rapidly.