Cliffy - about 25 years ago when I was a young fellow, my pard and I went on our first hog hunt. We figured we were well armed, he had a .44 mag Super Blackhawk and I had a .357 mag Colt. Almost as an afterthought I tossed a .300 mag Ruger 77 rifle in the truck too.
My buddy took the first shot at a fair-size boar (I'm guessing around 180 - 200 pounds), with that .44 mag at about 30 yards. He was a fine shot and had practiced often. The bullet smacked that hog a little high on the shoulder! Dirt & caked mud flew. We were startled to see the boar then beat the snot out of a smaller pig nearby, and resume rooting and eating...
What now my buddy asked? I whispered some sage advice "Shoot him again." Real bright eh? So he did. This time ol' Mr Boar figured something wasn't right and exited the area. With two hits from the .44 apparently not slowing him down in the least. Since we were enthusiastic, fit young fellows we gave chase. About a quarter or half mile later we came up on him in a clearing. He was waiting for us... Suddenly my .357 mag didn't feel like a very big revolver. The rifle was back in the truck. My buddy shot the hog again, but made his only poor shot, and the bullet sliced along the edge of the head, hit an ear, and showered the boar with blood.
Mr Boar decided he'd had enough and came at us. I had my "mighty" .357 out, and my buddy was yelling at me to not shoot, he wanted to finish the pig himself. Finish? I thought the pig was doing just fine and we were in deep trouble, but okay... So, he pops the hog with a fourth .44 mag, and the pig turns hard, and continues running. My bud is then able to trigger a 5th .44 mag into him. This one slips through the ribcage and ranges forward into the heart/lung area and Mr Boar piles up. It was pretty exciting to us deer hunters.
What we found out was that the warm-loaded 210 gr JHC Sierras were flattening out and barely penetrating on the mud, hide, muscle & gristle plate. Had he loaded 300 gr hard-cast or something similar, the hunt would have been over quickly. Back then, 25 years ago, we didn't know that and placed our faith in the powerful .44 & .357 mag revolvers we were carrying, with "average" bullets.
We field dressed the hog, pulled him out of there. Had lunch. I did some thinking and went to the truck and got my .300 Win mag, and a box of 180 gr Nosler Partitions. That did the trick on a smaller pig later in the day, one shot through the heart. No muss no fuss. Not saying a .300 is required for pigs, not at all, but they can take some killing. And they can dish out some pain if they take a mind to fight.
Dad laughed at our story. He always hunted them with a .308 Win or a .30-06 and found a good 165 grain deer bullet worked very well, head or chest.
Enjoy your hunt, but I think the .22 is best reserved for squirrel shooting...
Regards, Guy