I have probably shot more hogs here in East Texas that most guys ever will. I manage properties that have good populations of the them and shoot them both in the open and in traps. I have shot hogs with everything from .22 rimfires to full house 45/70's and lots of calibers in between. A hog can soak up a lot of punishment, but I sort of think maybe it's just a matter of something with their nervous system that takes a while sometimes to decide they are dead. I shot a running sow one time with a .350 Rem. Mag and she went another 30-40 yards before she fell over. When I cleaned her, I found her heart had been completely severed from the rest and just fell out of the cavity. Nowdays I shoot for the front shoulder and try to break bones as a way to stop one in the open, or to the ear shot from the side in a trap. Between the eyes with a .22 does a quick job as well in a trap. I've been trapping them for 3 years on one piece of property and have a count of 323 so far, with no real end in sight.....so I guess I'll just keep picking up what ever rifle I have handy when I leave the house. I think caliber selection is over rated for hogs, just take whatever you think will work and have fun. Those hind legs on a smoker are some pretty fine eating......
Sorry for getting so windy on the subject....