My weapon of choice for squirrels is a bow and arrow. I take two "squirrel arrows" to the stand with me every time I go out.
So at least I'm not the only one who designates an arrow or two for varmints. lol I didn't get a deer this year in bow season but I did shoot two squirrel's and a raccoon, muzzy's really do a number on them. It's fun, it's awesome practice, and it helps eliminate the 20 billion noisy squirrels around my tree stand.
But when the time comes for small game season and I want to specifically hunt for squirrels, I like a .22 or one of my other rim fires it adds a little challenge and excitement to the hunt where as the point and shoot shotgun gets a little boring. Besides if you ever eat them (not that you are in this situation) theres nothing like chomping on a pellet or two. lol