You've probably heard this before. Fire two shots to the assailant's chest and then another to the head. This drill was popularized by Jeff Cooper after he heard a story from a mercenary who fought in the Mozambique wars of the 1960s. According to the story the shooter fired two shots into the torso of the attacker who continued to approach. Surprised that the two shots to the torso had not disabled the attacker he then took a more deliberate shot to the head and stopped the attack.
Since the head is a much smaller target shooters are trained to always aim for the torso. The torso is a more consistent and larger target. That said the only shot placement guaranteed to fully disable an attacker is in the brain. Since the skull is very hard to penetrate shots need good placement even on the head in order to fully disable the attacker.
And so, with this in mind Jeff Cooper created and taught the “Mozambique Drill” teaching his students to take two quick shots to the torso and then a slower and more deliberate shot to the head.
To Train This Drill place your target between 7 and 10 feet out. Use a silhouette target or use two separate targets for the torso and the head. Start slowly with deliberate motions and then increase speed. Focus on taking a pause before the head shot to really ensure accuracy.
When this becomes easier add a second target to the side and practice the drill on both targets. You may try shooting all 4 torso shots and then returning for the head shots. Remember the idea here is to stop the attacker with the 2 shots to the torso then re-access the situation and take the head shot if necessary.