Friday, May 24, 2024

Biting The Silver Bullet 6: Is Stopping Power The Same As Lethality?

Sanjay Soni

Someone the other day asked me an interesting question – is stopping the power of a bullet the same as lethality? These are surprisingly not the same!

  • Stopping power is the ability of a firearm or other weapon to cause a penetrating ballistic injury to a target (human or animal) enough to incapacitate the target where it stands.
  • Lethality on the other hand specifically refers to how capable the ammunition is to cause death.

Stopping is usually caused not by the force of the bullet (especially in the case of handgun and rifle bullets), but by the damaging effects, typically loss of blood, and with it, blood pressure. More immediate effects can result when a bullet damages parts of the central nervous system, such as the spine or brain.

In response to addressing stopping power issues, the Mozambique Drill was developed to maximize the likelihood of a target’s quick incapacitation.

The Mozambique Drill is a close-quarter shooting technique in which the shooter fires twice into the torso of a target (known as a double tap to the center of mass), momentarily assesses the hits, then follows them up with a carefully aimed shot to the head of the target. The third shot should be aimed to destroy the brain or brain stem, killing the target and preventing the target from retaliating.

As I had written in my first article on lethality – it has been proven that the best way to improve the lethality of a fired cartridge is by improving the marksmanship of the soldier. The Mozambique drill follows on the same principle of improvising fighting techniques to increase lethality of the fired cartridge.

The Mozambique Drill

Rhodesian Mike Rousseau was serving as a mercenary in the Mozambican War of Independence. While engaged in fighting at the airport of Lourenço Marques (modern-day Maputo), Rousseau was armed with only a Browning HP35 pistol. As he turned a corner, he bumped into a FRELIMO guerrilla armed with an AK-47. Rousseau immediately performed a “double tap” maneuver, a controlled shooting technique in which the shooter makes two quick shots at the target’s torso. Rousseau hit the target on either side of the sternum, usually enough to incapacitate or kill a target outright. Seeing that the guerrilla was still advancing, Rousseau made an attempt at a head shot that hit the guerrilla through the base of his neck, severing the spinal cord.

Rousseau later related the story to an acquaintance, Jeff Cooper, who incorporated the “triple tap” or “Mozambique Drill” into his practical shooting technique. This technique later became popular all over the world for military personnel training , especially in anti-insurgency operations.

Lethality is defined as how capable something is of causing death. Every gun is lethal, the access to any gun creates risk, but some guns cause greater risk than others based on how they are designed and how they can be used. And it is not the capability to cause death that is at issue; it’s the capability of the bullet fired by the gun. And since different guns fire different types of bullets, and since every different bullet creates a different amount of damage, we can measure gun risk by combining the type of bullet delivered by a particular gun, plus how the gun is designed to deliver that particular bullet.

The Myth of the One-Shot Drop

In many of the classic cowboy movies from the early days of the American film industry, the stereotypical “good guys” wore white hats, whereas the “bad guys” donned black ones. After meeting in the middle of a dirt street in some small town, two shots would ring out. The bad guy’s bullet always missed, but the one from the hero inevitably found its mark and freed the town of the criminal threat. With one shot from the good guy’s gun, the bad guy dropped to the ground and became completely incapacitated.

Today’s films and television programs are generally more realistic. However, this has not always carried over to the portrayal of gun battles. Many current shooting scenes continue to display unrealistic reactions and underlying expectations about ballistic effects. For example, one shot from a handgun often lifts the wounded person two feet off the ground and causes immediate incapacitation. Even knowing that these are movies and television programs, some in the law enforcement community still expect one-shot drops in real-life shootings. In fact, few actual instances end this way.

On a summer evening in the northeastern part of the United States, a patrol officer received a radio dispatch at approximately 7 p.m. to respond to an address for a disorderly subject. The officer arrived at the location and parked his patrol vehicle on the opposite side of the street, several houses away. Before exiting the vehicle, the officer paused to observe the scene. He saw a male move from behind a large tree. The officer started to exit his vehicle, but then stopped when he saw the male, with a gun in each hand, begin to run towards him. The man fired both weapons at the officer, who returned two rounds from his service weapon, striking the male in the center of his chest. However, the man continued to fire. One round struck the officer in the head, killing him instantly. The male survived the two gunshot wounds and later was convicted of killing the officer.

Let us analyze the One Shot stopping power by Caliber

Greg Ellifritz at Active Response Training conducted a study analyzing data of 1,800 real world shootings that took 10 years to compile. He collected data from autopsies, forensic examinations, as well as case reporting to try and find an answer to the following questions:

  • Which calibers reliably stop threats?
  • Which are the most accurate?
  • And how much more lethal are shotgun and rifle rounds compared to pistol rounds?

The real question is, are there any concrete differences in stopping power amongst handgun calibers, and between long guns and pistols?

If we examine this chart we see that shotguns and all center-fire rifles have a much higher likelihood of stopping a subject with only one round fired. Greg defined this as an assailant immediately ceasing to shoot or fight after a shot. If they were running they must have dropped to the ground within 5 feet. It should be noted that this data comes from police and military engagements. Things like accidental shootings or suicides were not counted.

We should also be aware that this metric is derived by taking the number of incapacitations and dividing it by the number of rounds a person took.

You can see that generally as the size of the round decreases, the probability of a one shot stop decreases as well. However, we need to be careful here as we have one large confounding variable. Handgun calibers that are used in revolvers are more likely to have higher one shot stops because you cannot fire them as quickly as semi automatic firearms. This explains why the 44 magnum has a higher one shot stop percentage than the long guns. It is just slower to shoot a big, heavy recoiling revolver than it would be to shoot an AR15, or a 9mm semi auto.

The important take away from this chart is that there is less than a 10% spread between 38 special and 45 ACP. Practically speaking this may not even be statistically significant if we controlled the amount of rounds fired in an engagement.

To better grasp the scope and gravity of the myth of the one-shot drop, the authors of a study of violence against law enforcement officers provided an over view of felonious, line-of-duty law enforcement officer deaths.

From 1993 to 2002, 636 officers were feloniously killed in the line of duty.

  • Offenders used handguns, ranging from .22 to .50 caliber, to kill 443 of the officers.
  • Forty-five of these victims were slain with their own weapons.
  • Fifty-six of the 443 officers (12.6 percent) were killed by small-caliber weapons that fire lightweight bullets at low velocity and included .22, .25, and .32 calibers.

Undoubtedly, no officer would consider any of these firearms as a primary weapon of choice, and no records indicated that agencies issued any of these to their uniformed patrol officers.

Of the 45 officers killed with their own weapons:

  • 3 were slain with small-caliber rounds from backup/off-duty weapons they carried, either .22 or .25 caliber.
  • Twenty-five officers (56 percent) were killed with their 9-millimeter or .40 caliber service weapons, common to law enforcement during the time period examined.
  • The remaining 17 officers were slain with other weapons, including .38 caliber, .357 magnum, 10 millimeter, .44 magnum, and .45 caliber.

In two previous studies on violence against law enforcement officers conducted by the authors, 41 percent of offenders in the first study and 68 percent of offenders in the second study stated their reason for selecting a particular firearm as availability. These offenders did not care about bullet weight or velocity. Their major concern was being “fast on the trigger” and delivering the bullet to its intended target. One stated, “There’s no time to sight up the gun. If you hesitate, you’re dead.”

Law Enforcement Officers Feloniously Killed in the Line of Duty with Firearms 1993-2002

Size of AmmunitionTotal SlainWhile Wearing Body ArmorWith Own Weapon
.22 caliber2892
.25 caliber18111
.32 caliber960
.32-20 caliber100
.357 magnum30195
.38 caliber65285
.380 caliber43240
.40 caliber342411
.41 magnum110
.44 magnum1171
.45 caliber36245
.455 caliber110
.50 caliber110
7.62×25 millimeter110
9 millimeter1366514
9×18 millimeter110
10 millimeter201
Size not reported25100
Total44323245
Source: U.S. Department of Justice, Federal Bureau of Investigation, Law Enforcement Officers Killed and Assaulted, 2002 (Washington, DC, 2003).

Average Number of Rounds Until Incapacitation

This is another key metric that will tell us how much real world damage a round does to someone. This, along with our other metrics, demonstrates the realities of defensive shootings.

Smaller calibers tend to require more shots until the person is incapacitated. The 9mm round has the highest number of shots prior to incapacitation. I believe this is because it is one of the easiest rounds to shoot quickly. If we had more data, we might be able to see the probability of incapacitation given different round counts.

All popular self defense rounds require between 1.5 and 2.4 rounds before an assailant stops what they are doing. It is interesting to note that the .22 cal round is the same as the centerfire rifle. While this is interesting, I agree with Greg’s assertion that this is likely more of a psychological stop than physically destroying an assailant’s ability to continue to attack. This is sometimes referred to as “psychological incapacitation”.

We can see the same results from the study of violence against law enforcement officers, where officers used large-caliber hand guns with limited effect.

In one case, the subject attacked the officer with a knife. The officer shot the individual four times in the chest; then, his weapon malfunctioned. The offender continued to walk toward the officer. After the officer cleared his weapon, he fired again and struck the subject in the chest. Only then did the offender drop the knife. This individual was hit five times with 230-grain, .45-caliber hollow-point ammunition and never fell to the ground. The offender later stated, “The wounds felt like bee stings.”

In another case, officers fired six .40-caliber, hollow-point rounds at a subject who pointed a gun at them. Each of the six rounds hit the individual with no visible effect. The seventh round severed his spinal cord, and the offender fell to the ground, dropping his weapon. This entire firefight was captured by several in-car video cameras.

In a third case, the subject shot the officer in the chest with a handgun and fled. The officer, wearing a bullet-resistant vest, returned gunfire. The officer’s partner observed the incident and also fired at the offender. Subsequent investigation determined that the individual was hit 13 times and, yet, ran several blocks to a gang member’s house. He later said, “I was so scared by all those shots; it sounded like the Fourth of July.” Again, according to the subject, his wounds only started to hurt when he woke up in the hospital.

Greg’s Study: Percentage of People Actually Incapacitated by One Shot

This metric is a more straightforward look at people that were stopped by only one shot. These persons were hit with only one shot in the torso or head and immediately dropped to the ground, or ceased their violent action.

It is obvious that a shotgun and centerfire rifle stop assailants much better than any pistol caliber. I was also surprised how well .357 (both Sig, and Magnum) did. I wouldn’t put much stock in the data for .32 calibers, as there were only a total of 25 cases. This is likely not as accurate as the more common calibers. The takeaway is that there’s roughly a 10% difference in one shot stopping power amongst common handgun calibers.

Most handguns including the most popular 9mm have a one shot stopping record of less than 50% ! This is quite contrary to what is generally perceived by most people buying 9mm handguns for self defence.

Percentage of People Not Incapacitated

This metric looks at how many people continued their aggressive action no matter how much they were shot. I bet you can guess which way this trend will go!

Surprise, surprise, smaller bullets do not stop people as well. For the mouse guns, we can see that there is roughly a 1 in 4 chance that a bad guy will not stop no matter how much you shoot them. This percentage decreases to

between 10-15% for common handgun calibers. We can see that centerfire rifles are in the single digits.

Conclusion: If you truly want to defend yourself, get a rifle!

We will look into the lethality of various weapons in the next article using several different parameters.

Sanjay Soni is the Managing Director of Hughes Precision Manufacturing Pvt. Ltd., India’s first small-calibre manufacturer in the private sector. An MBA from the Indian Institute of Management, Bangalore, he has been involved with the ammunition industry in India and abroad since the last 8 years.


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