Boar, hog and feral pig shot placement.

Aim Low

A porcine vital area is considerably lower than a Whitetail Deer. For the most part, people are used to aiming behind the shoulder. With a wild pig, you need to be aiming lower, probably even lower than the vitals are shown on the diagram below. You are basically going to want to hit them just above the elbow for maximum heart/lung penatration.