Hard to describe without a photo. Picture the hog, from the ear, back towards the shoulder, from the top of the neck and down a few inches. Kind of a rectangular area.
If you aim too low, you will likely lo :-) se the hog, but a shot in that area generally drops them in their tracks. Too far back and hit the shoulder, you may not recover the hog, depends on his size, weapon used, penetration etc.... markc