I like a 22 if I'm gonna be setting still, preferably with a good fine-crosshair scope. My CZ 457 and Leupold 4x28 usually fill that bill. If I'm running behind a dog with the guys, I like to carry a shotgun, preferably my M12 full choke 16 gauge. However, I have been known to carry an iron-sighted pump 22 when it's "my turn" to carry the 22 on a dog hunt. Usually there are 4 or 5 of us chasing 2 dogs, and most guys will carry a shotgun. But, we have at least one 22 in the group for the ones that hold tight. A scope hinders more than it helps when dog hunting I think, since if they're running it's harder to get on them with a scope than it is with irons. A Marble's bullseye sight is excellent for both moving and still squirrels, as is a good peep, but I like the bullseye better.
Mac