Originally Posted by ArchAngelCD

Groundhogs are very tough critters. I have seen them hit with a .223 and practically take off a shoulder and they run away. Squirrels should be easier to kill but unless you hit something important they will not die quickly, like anything else. With a .22LR I would not aim for anything other than a head shot on Groundhogs. They will die quickly even with .22 Quiet ammo. (don't ask how I know)