Gimme a break
I have seen just about every caliber used at one time or another. From .45ACP up to .338 Win Mag. It's not the gun, it's the shooter.
Above is from my previous post. I still think that my post is correct. These are not armor plated super beasts.
Use whatever you can shoot well, and enjoy the eating that will follow. I have seen caribou taken with a .243 at over 200 yards, and they are certainly larger than 90% of any boar that you are likely to see.
I just rembered that 3 years ago my son took a boar with a .44 Spl. at about 65 yards.
1 shot, DRT.
Nuff said