Go to a leather store, buy some 1" saddle leather a small piece will do, behind it place 2" of wet newspaper, behind that a 2"x4", then some more paper2" , followed by a piece of 1/4" plywood, then a gallon jug of water, repeated with the same sequence on the other side, make a sandwich with the water in the middle. If your load won't punch through that whole mess and come out the other side, it isn't stout enough to kill a good boar hog. Cut the leather to 1/2" if you are only going to shoot sows.
Hogs are tough animals, they can soak up abuse like few critters on the planet. I've put 405gr .45 caliber bullets through both front shoulders at less than 50yds and had them run off, often their shoulders won't shatter like a deer. If you limit your shots to less than 10yds, shoot only with a frontal facing hog, into a spot between the eyes and one inch high, you can kill one outright with a small pistol.
If you want to spend your hunt doing more than tracking hogs you crippled, pick a real handgun hunting cartridge, save the semi-auto self defense stuff for coyotes, bobcats, and fox. I've taken a few with a .357 magnum and 158gr fodder, but only with dogs present and a close frontal shot. I've killed some other with some 180gr XTP handloads out of a .357, that I wouldn't shoot in anything that didn't say Ruger. They'd bust both shoulders at less than 20yds almost all the time; notice I said almost.
I could tell you stories all evening of hogs that soaked up unbelievable amounts of lead and kept on running, headshots that got up five minutes later and walked away, hogs that took a 1oz slug from back to front lengthwise and required a second shot. They are tough animals and if you cripple one, and then corner him, he will fight you tell one of you isn't fighting anymore. All the crap you hear about them stalking you is pure bunk, over active imaginations, but if you back one in a corner, you better believe you will have a fight, and that .357 sig or 10mm will begin to look real small.
I faced one down one day with a 1911 and some 230 gr Gold Dots that another guy crippled and it was not fun, and it took four rounds with him charging to hit paydirt. The head was down and all I had was a spinal cord to hit, covered by about 4" of meat. He's dead and i'm not, but I had somebody looking out for me, God looks out for little kids and fools, I was 25 so you decide.
I won't say buy a .45/70, most of mine have been with a .280 lately and some 150gr corelokts. But with a hog an exit wound is a must have, or he will get away sometimes.
I have killed em with a .22 magnum before, but that doesn't mean it is the best way to do it. I shoot enough of them I can wait, be picky about my shots, or not shoot at all and it really doesn't matter if I bring one home or not. But if the freezer is empty and I need pork, I grab a rifle and some stout bullets.
