I would use 000 if you can get it. But 30 yards is way to far to bee shooting at big hogs with a shotgun. Do you have dogs? If you are hunting with dogs then use a knife. Even a bow is better than buckshot on a hog, so I would take that if you have a stout bow.
Bows will kill pigs, but don't expect them to drop quickly and it is best (and safer) to hunt them from a stand. The small pig on the right took two arrows, one to the head/neck and one to the body, and ran a good distance before dropping from the second arrow to the body.
