I seen a dude try to put down a dying cow with a .38 to the head at point blank range. It did not penetrate the skull or kill it. He didnt know shot placement lolLots of slaughter houses use a .22 (hammer? don't remember the name) to kill animals. Before that, they used poleaxes. My Dad used to kill steers with .22 shorts when they did their own butchering.
Shot placement rules.