At my father-in-law's farm, I once shot a 60 lb sow right between the eyes with a Ruger .22 pistol loaded with high-speed HPs. The bullet bounced off. I could hear it whistle as it tumbled end-over-end out into the corn field.
She squealed and ran a few feet, then shook it off and went back to eating. I shot her twice through the lungs. She didn't seem to mind very much. Finally, I got a slug into the back of the skull and she went down.
Needless to say, I don't think much of the .22 as a SD cartridge.