Check the regulations for your state. If there are restrictions, it shouldn't be hard to find.
When I lived in Florida, they went to a squirrel restriction for one season, for one area, for only the one year. You were only allowed a single-shot pistol; with iron sights; no more than an 8 inch barrel; and only .22 Short, BB cap, or CB short ammo (exactly the same as some of the 'coon seasons). Like I said... it only lasted one season, in the one experimental area - too many hunters complained (mainly, about the single-shot pistol requirement - they're not as common as they used to be).
"Such is the strange way that man works -- first he virtually destroys a species and then does everything in his power to restore it."