Stopping drills, also known as failure drills, or failure to stop drills, are a close quarters shooting technique that requires the shooter to fire multiple rounds into the target's center of mass, quickly assess whether or not the target is still a viable threat, and if so, deliver a killing shot to the head.
Stopping drills, according to anecdotal history, were originated by mercenary Mike Rousseau. While fighting in the Mozambican War of Independence, he encountered a guerrilla fighter at close range. Armed only with his handgun, he fired twice into the guerrilla's chest. After lowering his weapon to the ready, Rousseau noted that his shots had failed to neutralize his target, and so sighted in again and fired a third shot that struck his target in the neck, severing the target's spinal cord and neutralizing the threat.
Some time later, Rousseau related this experience to an acquaintance, retired Marine Corps Colonel Jeff Cooper. Cooper integrated this technique - then referred to as the "Mozambique drill" - into his "modern technique" of pistol shooting, and the drill slowly migrated into the common curriculum of tactical shooters. A significant adaptation to the technique took place over the course of time, with the new technique no longer calling for the shooter to return to the ready position to evaluate the target after the initial shots have been fired, but to instead keep the weapon trained on their target until it has been adequately neutralized with the follow-up shot to the head.
Later developments include variant methods, such as calling for the initial shots to be delivered to the target's hips or knees, with the follow-up stopping shot still being fired at the head.
The overriding notion behind stopping drills is to provide a shooter with the training and capability to decisively and quickly terminate an engagement with a given target.
No matter how or where the initial shots are placed, it is critical that the stopping shot be fired to a location that destroys either the brain or that causes catastrophic damage to the spinal column at or above the neck, so as to render the body incapable of functioning, even if the target is still alive.
Against an unarmored human target, gunshots to the torso generally cause catastrophic damage to the vital organs, often guaranteeing death. Despite this, the target may continue to live and be capable of conscious action for several seconds or even several minutes, and still pose a threat to the shooter or friendly forces. This is what necessitates the rapid, decisive stopping shot to the head or upper spinal column. Against an armored human target, the shots to center of mass may cause little or no permanent damage, and may do nothing besides momentarily stun the target, requiring the same stopping shot.
With a zombie in mind, shots to center of mass are not advised, though a spinal hit would render the target unable to use its legs. That said, a variant of stopping drill may be beneficial in certain situations. Firing shots into a target's hips, pelvis, or knees generally cause enough damage to render the human body structurally unsound, similarly making it physically impossible to walk, and could very well serve to give the shooter enough time to accurately and more easily lay in a shot to the head.
The latter method of stopping targets could also be used in a tactic unrelated to failure drills, wherein sustained, withering automatic gunfire is directed from several sources at knee to torso level across a wide front of massed zombies. While this wouldn't be immediately lethal to the zombies, it would allow a much smaller force to project much larger capability than if they tried to stand and pick off individual targets that approached them. While resource-intensive, this tactic would leave the shooters with a vast number of targets who are no longer advancing at walking pace, but are instead stumbled and fallen, trying to crawl forward, with nonfunctional legs. The shooters could then advance forward in a skirmish line, annihilating their prone targets at whatever pace they liked.
Applicable Weapon Systems Edit
While there are a great many differences in the tactical employment of different sorts of handguns and long guns (for example, revolvers as compared to pistols, or submachine guns as compared to rifles), stopping drills can be practically and effectively executed with almost any sort of firearm that allows for semiautomatic fire, save for shotguns, which are so specialized a tool as to require their own methods of employment.