The answer to this question is more complicated than it might seem. To get a clean kill, you have to understand the anatomy of turkeys and the best places to shoot them.
Shot placements on gobblers vary from broadside shots to headshots, but a majority of the time you'll be shooting from the back or wing. For those shots, aim where the arrow butts into the bird's body. This will either break the wing, hit the spine, or cut the lungs or heart.
Aiming in the head is another difficult spot to get it right. The erratic movement of turkeys makes this shot challenging. Ask your archery shop about broadheads specifically designed for head-shooting.
When you are aiming for a turkey when it is facing you, aim four inches below the base of its neck. This will make the arrow immobile and severe its spine, killing it in the process.
You should also aim in the area of the center of the turkey's back. This will cause the turkey to be immobile and severe its spine, killing it quickly and ethically.
A turkey's vitals are roughly the size of two fists closed together, which is much smaller than the vitals in most of the top game animals pursued with archery equipment. Understanding this vital area will help you shoot in the right places and avoid wounding a turkey unnecessarily, which can affect the meat inside and lead to ethical kills.