For something like squirrels in trees, a shotgun seems to make sense - perhaps a little safer for when those pellets that miss come down. For anything on the ground, shoot whatever you want. I've been carrying my .357 Mag revolver with my hand-rolled cowboy loads. It's cheap to shoot, and the one rabbit I took with that combo this winter showed less meat damage than what I've seen with some .22lr HPs. I purposely took a shoulder shot just to see what kind of damage it would do. Moving forward, I'll probably opt for head shots.
