I don't pay much attention to statistics, as I have been charged twice by big hogs. The first time, i was deer hunting, it had become dusk, and I was climbing out of the treestand. Maybe the big 375 pound boar didn't see me, but he was coming straight at me, and very fast. For me, everything went into slow motion, and as I was shooting, the scene from the old tv show (it had just come out then) where one of the kids was killed by a charging boar came into my mind.
It took 3 shots from my 30-06, and I distinctly remember each shot, and the boar collapsed from the third shot to the head about 10 feet away from me. My parents and ranch hands, who were about 500 yds away, all said they only heard one "big" shot - I was shooting fast.
The second charge wasn't so exciting, but they have had a profound effect on me.
I always go armed when outdoors, and carry a caliber that starts with a 4. Penetration to the vitals is the key, and it may seem counter-intuitive, but a keith, or wide flat nose, long flat nose, all penetrate more deeply with the correct loads than a 30-06 with 150 grain Remington "core-locks" (ok, this was before I handloaded and we didn't have all the super premium bullets easily available).
For my use, I rely on S&W N-framed revolvers, but in deference to Ted Nugent, I also sometimes have a Glock 20 10mm with me.
Whatever you decide, you will need to practice a one-handed draw plus shooting with one hand since you will likely be pulled by one scared and skinny dog.
I have had many more encounters, however, with feral dogs and coyotes than hogs. A 357 or even a 22 mag works ok with feral dogs, but you don't get to choose your circumstances, so you should carry the largest caliber you can practice with often and shoot well.