I think this statement pretty well summarizes my feelings on caliber selection. If I'm going to the trouble of driving out to my hunting spot (it costs me ~$15 in gas round trip at today's prices), buying or bringing along a meal for the evening, plus the time and effort involved, I want to be pretty certain that any hog I shoot at is going down. Sure, .22 ammo is cheap and the rifle is lightweight and easy to carry, but if I spot a hog 125 yards away in a pasture, I want to be able to shoot at it with some confidence.

Likewise, if I wound one and have to trail it into the brush, I want more than just a .22 in my hand when I find it.
. . . Of course, that's why I usually bring along my .45ACP