.45 on wild pig

[MeekandMild]

When I was a teenager I worked for a farmer. One year we had to go out into the woods to capture the yearling hogs which had escaped, bring them back and castrate them or if we couldn't catch them we had to shoot them with a .22.

I don't think I'd do that again without a good stout spear.

 

[AKAMac]

Diggler,
I would go with the 243 using Nosler or BarnesX bullets. Some of the factory premium loads are very good. Remember that these are tough animals and they will go a long ways with gut wounds. If you can have your son practice with the rifle he will use and if you can try some moving targets with him you can make this a lot of fun.
You can get an old tire and staple some cardboard in the middle. Have a friend roll the tire (be sure that the friend is safe) about 50 yards in front of him. Use cheap ammo for practice then sight the gun in with the good stuff.
If your friend holds the tire on his thigh with both hands and lets it roll down his leg and "Kicks it off" as it nears the ground you can get some good speed on the target. Be sure to have your son hold gun up until you call shot.
Good luck. Mike