Lots of good options, but for a new gun, I'd opt for a CZ. That said, I have two favorite squirrel getters. The bolt action (per the OPs interest) is a Remington 541T with a sporter barrel. The other, an over-and-under break action, is a scoped Savage 24 in .22mag/20 gauge. I find that I actually carry the latter more often in the squirrel woods; like the 20 gauge for rats up in the trees and the .22mag for shots with a good backstop..