I have taken hogs with 357 Mag, 357 Sig, both 44 Spl & Mag, 22 LR, 223, 243, 30-30, 308, 7.62x39, 7.62x45, 7x57 and probably a cpl other rifle calibers I can't recall just now. They're not THAT hard to kill w/accurate shot placement.
Outerspace, Accuracy is the word. Neck and ear hole shots are preferred if you want to drop them immediately. 30 cal for shoulder, neck, and ear. You don't want to stun them or just wound them because a large sow or boar will get you quick. Shoot straight and fast to get as many as you can.
Some hogs, not all, have scar tissue which forms a type of armour plate over the shoulder. It takes serious penetration to bust through it for a good heart / lung shot.
Shoot any hog right behind the ear and it will drop like a rock. Breaks the spine.
I would not count on the semi-auto AR-15 feature if you are on the ground in the woods, some hogs can take quite a few before going down ....
Outerspace,
a large boar can absorb a lot of bullet. i.e. 7mmmag 175 partition at less than a hundred yards took a shoulder shot that did not go thru, rather the boar charged in the direction of my stand and circled and died about 75 yards from where it was shot. The 7mm mag did not knock it down. It had a shield of 1.50" and 3.5" of razor tusks.
Be careful, the first shot counts the most. After that shoot as straight as possible at good targets.