A .22 caliber bullet will put a pig down if you hit it in the right place...
Shot placement is the key to taking anything down, a 300 grain bullet will do a ton of damage, especially a hollow point...
I would suggest you carry a back-up gun, (6 shot .44 magnum prefered) hey, you could miss and have 300 pounds of ticked-off hog charge you... :shocking:
By the way, how fast can you reload? :winking:
The load you chose should kill the hog without too much concern, providing you shoot it in the right area...