The Gamo .177 with pointed hallow points will fire through a deer skull at 45 yards. and at 50 I can take cloths pins off a line. I think a head shot will stop a squirrel with ease. and I really don't think it would survive a chest shot.
i got mine to take out feral cats.
I do agree a .22cal would have more punch. I got mine at bass pro. they have a nice selection of air riffles and you can pic them up and hold them ... i got the Wisper because of the scope and stock it had. had the best fill for my long arms and the scope was NICE...
When i die bury me upside down so the whole world can kiss my ass.