I have never hunted hogs.
I do have a friend who used to do so. I remember his slow progression from 44 magnum rifle, to 444 Marlin, to 416 Remington Magnum. I guess the progression of cartridges corresponded with the frightening encounters with really big feral hogs who when shot, wouldn't just lie down and die, but who would attack him in his blind.
Like I said, I haven't hunted these critters, and 416 Remington Magnum may be a really big cartridge, but I think I would take a lesson from Gary and start at that point.
YMMV