For those attempting a suicide aiming at the chest, the heart is target. Deflection by the ribs can be an issue. Stone suggests aiming under (or between) the left side ribs, with an upward trajectory toward the right side of the neck. Even if fatal heart damage is not caused, there is a fair chance of fatal results by hitting either the aorta (largest artery) or the vena cava (largest vein), or their major branches.
Using a shotgun if aiming at the chest will also increase the chances of a fatal outcome due to the fact shot spreads out and can cause extensive damage even if not aimed quite correctly.
