I haven't had any rat or ground squirrel get away with my .25 Marauder. The modified crow magnum pellet shreds them. Head shots, body shots, doesn't make any difference. I really like my .25 Marauder!!!
Steve p.s. ShootingChrony Inc. is a terrible company to deal with. Buy a Pro Chrono by Competition Electronics...they're made in the U.S.A.