I've seen those fat little buggers killed with everything from a .22 LR to a .44 Mag, and even an old English Sheppard we had one time. You should have seen it, the hog in an old milk can on it's side, in a junk pile and a space about 20"x 20"x 20" in front of the opening. Well that old hog got rousted out of that milk can by banging on it with a steel t post, and the dog and hog went at it. Round and round they went, growlin, hissing, biting and yiping, looked like a couple of fur pelts in a cyclone. Seemed like forever finally there was a crunch and that goofy dog tried to bring that fat ol hog through a hole in the junk about 6-8" wide. Sure do miss that ol' dog.
I just had to relate that story. Anyhow, I'd go for the Velocitor ammo and sight in the rifle at about 50 yards. Anything closer won't matter, and those Velocitors will give that ol hog heartburn in more ways than one. I've used them on ground squirrels and with a lot of luck and Kentucky windage, killed them at 200 yards with a 10/22. (Well sure, it took a few shots, but he was dumb enough to pop out of that hole enough times to walk the round in). Point being, take the .22, take a bunch of ammo and have at it. They like to sun themselves too, so just sit quiet and those lil' guys wiill be poppin out like crazy. You may get lucky and find a few foxes making residence in the old hog dens too!!