By now you should have scouted the area, picked out where you're going to hunt, reviewed all of your game camera pictures, set out any baits and attractants and you're now in your stand or hunting spot waiting for the hogs to show up. In many cases, you're going to hear the hogs coming long before you will actually see them. Hogs traveling through the woods are loud, running over anything in their path, and they squeal and grunt. So you now you've heard them and been listening for several minutes and they finally break out into the opening and find your bait. Suddenly you're staring at several sows and their offspring milling around eating, when suddenly a large trophy boar steps out. Now what?
Now is the time to put everything that you've learned to use and take that trophy hog but there are a few things you need to know before you loose that arrow or pull that trigger. Hog are not deer and if you attempt to shoot a hog where you would normally aim if it were a deer then most likely you'll end up with a gut shot and possibly miss your chance at bagging the monster. The heart and lungs are actually forward and lower than where they would be placed if it were a deer, so remember that and make your shot accordingly.
Before I go any further, I'd like to point out that our preferred shot on any hog is a neck shot. A shot on or near the spinal cord and brain stem will cause immediate incapacitation and in most cases instant death and a neck shot offers a larger target area than aiming for the brain only. The spine on a hog runs from the base of the skull through the midpoint of what would be the neck to just above the front shoulders. I will aim just below and to the rear of the ear and a good shot in this area will bring any hog down quickly. So my advice is neck shot, neck shot, neck shot.
If for whatever reason you want or need to take a lung / heart shot then the best spot for a standard broadside shot will be through the forward portion of the front shoulder and low into the chest. With enough penetration this will provide a double lung, heart shot and will be a fatal shot. For a quartering away shot you should aim for the exit, meaning that you should aim for the spot that will cause the bullet to exit directly between the front shoulders in the lower part of the center of the chest. This should provide a single lung, heart shot. For a head on shot, aim for the center of the chest.
1. Location to aim for a heart shot
2. Location to aim for a neck shot
From the diagram you can see how a neck shot gives a little more latitude on the accuracy of the shot. If you miss forward you can still hit the brain, if you miss low there's still a chance of hitting the heart/lungs. A miss high may still put the hog down but a miss much further back may be trouble.
In taking the above referenced heart / lung shots, remember that smaller caliber weapons may have trouble penetrating through the combination of bone, muscle mass and scar tissue in the shoulder of large adult boars with enough energy left to put the hog down quickly, if at all. If this is a concern then you can always take a head shot but as noted before the brain on a hog is a very small target and can be difficult to hit at distance and a face shot hog can run off to die a slow and miserable death. If you find yourself in this situation then take the neck shot. Another bonus to a neck shot is that it won't destroy the head and a good taxidermist will be able to repair any damage if you decide to have the hog mounted, not to mention you save a front shoulder or two.
If something happens and you make a bad shot and gut shoot a hog you could be in for a very long and arduous tracking experience. A gut shot hog can go a long, long, long, long way and sometimes there won't be much of a blood trail. If you completely miss your spot and shoot even farther back and hit a back leg or the pelvis then you could be in luck because this will usually immobilize the hog for a quick follow up shot. If you do end up with a wounded hog be very careful because they can be extremely dangerous. It would only take a split second for a large boar to seriously injure or kill a person so you must pay much respect to a wounded hog and finish the job from a distance if at all possible. This brings up the very last tip for this section, be very wary of a sow if you shoot one or more of it's offspring. From experience, she will be madder than hell and could possibly charge you if you are anywhere close.