I would have never imagined that a .22LRis a cartridge you would want to use for hogs. I would guess it would have to be a head shot and anything less would just get them pissed off at you and even with a head shot it better be a good one.
If I had the option, I would use something with a little more beef. Something that might break a shoulder or sumpin. I guess you could poke him in the lungs but that might lead to a difficult recovery due to a poor blood trail. Them pigs clot up good and fast and the fat just seems to fill in the hole.
If you do opt for the .22, just make sure your next to a climbing tree. Good luck and god speed. You might need it.