Scopes such as the ones mentioned above are Hunting scopes and set parallax free @ 100yds. If your going to take a head shot at a squirrel, at 25yds, with a scope set parallax free @ 100yds, you could easily miss......

With that being said, shots with .22's usually average out at about 50yds so you should look for either a rimfire scope, a scope with an AO or a scope that is set parallax free @ 50yds from the factory (some companies will set it for you). Mueller Optics will set the parallax on their 2-7x32 and their 3-9x40 for 50yds if you order direct....

CB