well it really depends i guess
i use a crosman 760 at 625fps at 10 pumps and i always pump it 15 times. pellet shape and weight make a big difference. for example, my pointed copperhead pellets go straight through a crow at 20 yards andit fliesanother 40 yards til dropping, but my hollow points nailbirdsand canput a 1-inch hole in a morning dove on impact at about the same distance anddrop it right there. the birds i would use wadcutters, hollowpoints, and domed pellets. the gamo raptors sound good and copperhead or crosman hollowpoints and wadcutters always work fantastic too. for squirrels i would have wadcutters, domed, or pointed pellets. woodchucks i would use domed or pointed and you might want to put a cheap $10 daisy scope on it