If you enjoy squirrel hunting and like to eat the critters ( I do!) then I say shoot'em with whatever you like. Nothing particularly sporting about wounding the animal with a misplaced .22 shot or using a .410. That's just one man's opinion, of course.
Using a .22 with good optics is a grand way to practice for still hunting big game. If you can sneak up on a squirrel you can do the same with a deer. I've found that sub-sonic .22 hollow points kill reliably if I do my part and only take sitting shots. The sub-sonics don't have the crack that shuts down the woods like regular ammo does.
What do I use? A good bolt action .22 with a 1" diameter scope and sub-sonic ammo. Or if I'm in the mood a 12ga Lefever G grade with #4 shot. Over-kill? Nah, it just makes for a reliable kill without small shot screwing up the meat...Geo
