The Myth of Energy Transfer

[Pathfinder76]

Interesting read.

Firearms Tactical Institute


Tactical Briefs #3, 15 March 1998

The Myth of Energy Transfer

In June 1994, Nicole Brown-Simpson, former wife of star pro-football player O.J. Simpson, was murdered on the secluded front walkway of her condominium when someone cut her throat with a knife. How long do you think she remained conscious and able to perform willful activity? How much kinetic energy do you think was "transferred" from the knife blade to the soft tissues of her throat?

Nicole Brown-Simpson collapsed unconscious very quickly because the knife blade ruptured the carotid arteries and jugular veins in her neck, causing massive loss of blood which deprived her brain of vital oxygen needed to remain conscious and function.

When you shoot an attacker in the torso, the goal is to produce fatal hemorrhage by rupturing the heart or a major blood vessel so he will quickly collapse. This is why shot placement is so important. These vital structures lie deep within an average-sized person's torso, and you should choose a bullet that will not only penetrate deeply enough to reach them, but to go through them and crush a hole in them from any engagement angle.

There have been many police officers here in the United States who've been shot with medium-high energy Magnum handgun bullets (as well as shotgun slugs) while wearing soft body armor. Soft body armor is constructed of several layers of fabric. When a projectile impacts soft armor, its energy is transmitted directly through the flexible fabric to the officer's body. There's not one documented incident in which an officer was knocked unconscious or physically incapacitated or in any way rendered unable to perform willful activity after his soft armor stopped such a projectile. These officers absorbed nearly 100 percent kinetic energy transfer, yet none were incapacitated by the blunt trauma "shock" of projectile impact or temporary displacement of underlying soft tissues.

When soft body armor is tested to meet National Institute of Justice (NIJ) certification, a single armor panel is fitted against a large block of very stiff oil-based roma-plastilina modeling clay. When high energy projectiles, such as Magnum handgun bullets or shotgun slugs, are shot into the armor, the resulting collision produces a deep depression in the clay behind the armor (provided the armor stopped the bullet). This dent (referred to as "backface deformation" by the NIJ) is representative of the temporary cavity produced in the human torso by the non-penetrating projectile. However, because of the stiffness of the clay, the dent is not as deep as the temporary cavity dent produced in the human body.

Soft armor appears to actually provide better protection when it's worn on a human body than when it's backed by clay during certification testing. The apparent reason is because the human body's greater flexibility and resilience, which acts as a better shock absorber than stiff modeling clay. This shock absorbing effect decreases the stress on the armor, which in turn increases its effectiveness. Cardiopulmonary Resuscitation (CPR) is a good example of the body's resilient shock absorbing quality.

Any handgun bullet you shoot into an attacker's body will deliver less energy than the energy transferred between the shoulder harness of a seat belt and the upper body of a 180 pound person during a head-on auto collision into a fixed object at 25 miles per hour. Consider the amount of "kinetic energy transfer" experienced by a NASCAR driver who survives uninjured, remains conscious and walks away from a spectacular collision at Daytona motor speedway, where speeds are almost eight times greater. A football pass receiver absorbs far more energy in his body, his internal organs subjected to much greater jarring shock, than any handgun bullet can deliver when he's running as fast as he can (15+ miles per hour) and makes a flying leap to catch a pass that's just out of his reach, and his body collides with the ground.

In November 1992, South Carolina Highway Patrolman Mark Coates shot an attacker four times in the torso with his 4 inch Smith & Wesson .357 Magnum revolver. His attacker, an obese adult male who weighed almost 300 pounds, absorbed the hits and shortly thereafter returned fire with one shot from a single-action North American Arms .22 caliber mini-revolver. Coates was fatally wounded when the tiny bullet perforated his left upper arm and penetrated his chest through the armhole of his vest where the bullet cut a major artery. Coates, who was standing next to the passenger-side front fender of the assailant's car when he was hit by the fatal bullet, was very quickly incapacitated.

The slaying was recorded by the video camera mounted in Coates' cruiser. For our law enforcement readers, a copy of the video was obtained by Calibre Press a few months after the shooting, and is shown at their Street Survival seminar. Frames from the video are published on page 238 of the Calibre Press book, Tactics for Criminal Patrol. (The Coates shooting is also presented in detail on pages 239-240.)

After Coates was hit, he immediately ran several feet, scrambling around the front of the assailant's car while simultaneously radioing dispatch that he'd been shot. As he neared the driver's-side front fender he suddenly collapsed onto the pavement.

Trooper Coates fired four 145 grain Winchester Silvertip .357 Magnum bullets directly into his assailant's heavy abdomen, achieving solid hits with each. These particular bullets penetrate deeper than 125 grain JHPs, however none ruptured any vital cardiovascular structures. During the initial ground struggle, Coates was shot twice, but his vest protected him. After fighting off his attacker, Coates quickly climbed to his feet and emptied his revolver. At that particular moment the assailant was still lying on the ground. The combination of the assailant's obesity and the unusual angle at which the bullets entered his body worked to the disadvantage of Trooper Coates.

The Coates shooting exemplifies the fable of energy transfer, especially when encountering a determined attacker. The .357 Magnum cartridge is regarded by many as the ultimate manstopper; a true one-shot stop wonder. The Winchester 145 grain .357 Magnum cartridge is given a one-shot stopping power rating of 86 percent by Marshall and Sanow. According to this rating system, a single hit ANYWHERE in the torso is supposed to be highly effective in stopping an attacker, regardless of whether or not the bullet destroys vital tissue. But on this night, it failed FOUR TIMES! The assailant easily absorbed four bullets in his body, each delivering over 450 foot pounds of kinetic energy. This is equivalent to being hit four times by a baseball going approximately 210 miles per hour.

None of Coates' powerful .357 Magnum bullets were effective, but the bad guy's weak .22 caliber bullet was. The .357 Magnum bullets dumped all their energy into the attacker, whereas the single .22 caliber bullet disrupted vital tissue. The assailant survived the shooting, was convicted of murdering Coates and was sentenced to life in prison.

Another shooting that was captured on video helps explain a reaction known as psychological collapse.

A few years ago, two Houston police officers cornered a suspected motorcycle thief at gunpoint against a chain-link highway perimeter fence. Upon being cornered, the suspect drew a revolver and threatened to kill himself. After negotiating for awhile, the officers convinced the suspect to put down his gun, and to catch and put on a pair of handcuffs that the officers were going to toss to him. The confrontation ended after the offender obtained the handcuffs, then reached to pick up the revolver that lay on the ground beside him. Despite a warning, he grasped and lifted the weapon. One officer opened fire with a Colt Government Model .45 ACP. Upon being hit in the right shoulder by a 230 grain Federal HydraShok JHP bullet, the surprised offender's facial expression instantly conveyed shock, horror and utter disbelief.

As he immediately slumped unconscious onto his left side, two more HydraShoks perforated his right upper arm and buried themselves in his right upper torso. The second officer, startled into reacting by the first officer's gunshots, fired several rounds from his Colt Combat Commander .45 ACP. He attained a single hit with a 185 grain Federal Hi-Shok JHP bullet, which perforated the offender's left arm and grazed, but did not enter, his left upper torso.

The offender survived the shooting, and according to Houston Police, the only vital structure hit by any of the bullets was the brachial artery of the right upper arm, which was repaired during surgery. The initial wound could not have caused the offender to collapse unconscious from blood loss as quickly as he did, nor were any central nervous system structures disrupted by the bullets. Although he rapidly collapsed unconscious after the first bullet struck him, there was no physiological reason for him to do so.

When a person is shot in the body with a handgun and falls down unconscious within a half-dozen seconds, it can only be attributed to a psychological reaction to being shot. This person simply faints from the sudden realization and fright that he has been shot, not from blood loss or any other reason. (This discussion does not apply to rifle bullets. Obviously, wild animals that immediately collapse after being shot by a centerfire rifle bullet do not faint from fright. The wound dynamics of rifle bullets are markedly different, but the physiological mechanisms are identical.) In order to be FORCED to collapse an attacker must lose at least 20 percent of his total blood volume (unless the bullet damages his brain or cervical spinal cord). This will take several seconds to occur, even with a direct hit to the aorta or vena cava with a large caliber bullet.

Most "stops" are psychological, not physiological in nature. The bad guy either faints or makes a voluntary decision to stop what he's doing. It's possible that a bullet with more "wallop," one that quickly delivers its energy and produces more blunt force sensation, might play a role in producing psychological collapse. But, psychological reaction to being shot is highly erratic and unreliable. It doesn't happen to everyone, especially a highly motivated attacker who's determined to cause as much harm as he can before he's stopped.

Unless you're clairvoyant, you cannot predict the exact circumstances of any self-defense situation you might find yourself in. Therefore, your goal in choosing a bullet for personal defense should be to select one that will be effective in as many different scenarios as possible. Your bullet must be able to penetrate deeply enough to contact and destroy tissue that is critical to the immediate survival of your attacker.

The two most important factors in stopping a bad guy are: 1) where you place your bullets, and 2) what organs your bullets penetrate and damage.

How much penetration is adequate? According to the nation's most prominent wound ballistics experts, your bullets should penetrate at least 12 inches of soft tissue. Penetration beyond 18 inches is considered too much, and a less penetrating design should be considered to optimize the cartridge's wounding potential.

But with small caliber cartridges such as .22 LR, .25 ACP, and .32 ACP (and sometimes .380 ACP), you're better off selecting a non-expanding bullet that might exceed 18 inches of penetration than to choose a bullet that expands and underpenetrates. When a bullet expands, the increased diameter and non-aerodynamic shape acts like a parachute to quickly slow and stop the bullet as it penetrates flesh. These tiny bullets lack the mass and momentum to achieve adequate penetration after they expand.

Bullets that meet the 12-18 inch penetration guidelines have proven to be very effective in police shooting incidents that have been investigated by reputable researchers who use the scientific method. These findings have been verified and validated by other distinguished wound ballistics researchers who've fully reviewed the data. These findings are far superior in validity to the Marshall/Sanow "one-shot stopping power" junk-science that is published in newsstand gun magazines.

There are a lot of people who've been deluded into believing that legitimate wound ballistics researchers simply shoot bullets into ordnance gelatin and ignore shooting results that show how effective these bullets are in stopping an attacker. This kind of faulty research would be incredibly absurd, wouldn't it? Do you really believe these researchers are that incompetent or ignorant? Their work wouldn't pass peer review or be accepted as valid by the scientific community. However, these scientists don't publish their work in newsstand gun magazines for financial gain, and they really don't care what the general population chooses to believe. These researchers publish their findings in professional journals, where it's available to people who are truly interested in the data.

The concepts of placement and penetration are simple -- too simple for some people to accept -- but these factors are the most important in stopping a homicidal attack.

What bullet is best? It's one you can shoot accurately under stress that's capable of penetrating deeply enough to inflict fatal hemorrhage and reliably functions in your gun. There's nothing mystical or complicated about handgun ammunition wounding effectiveness. It's simple: placement and penetration.

Originally Posted by chuck

What bullet is best? It's one you can shoot accurately under stress that's capable of penetrating deeply enough to inflict fatal hemorrhage and reliably functions in your gun. There's nothing mystical or complicated about handgun ammunition wounding effectiveness. It's simple: placement and penetration.

Not sure they needed to add the caveat about hangun ammo there. From my experience it applies to rifle ammunition as well. Good read!

[roger]

im convinced that deer have been wearing soft armour things these for years.

[Grizzly Adams]

Originally Posted by sheephunter

Not sure they needed to add the caveat about hangun ammo there. From my experience it applies to rifle ammunition as well. Good read!

I guess, I beg to differ. One of my favorite experiments. Take two, one gallon plastic milk jugs, fill with water and cap. Shoot one with a .22 LR and the other with a .223. Then, tell me there isn't very much more energy transfer, in the latter.

Grizz

Originally Posted by Grizzly Adams

I guess, I beg to differ. One of my favorite experiments. Take two, one gallon plastic milk jugs, fill with water and cap. Shoot one with a .22 LR and the other with a .223. Then, tell me there isn't a very much more energy transfer, in the latter.

Grizz

No need to beg anything. All you are seeing is the temporary wound channel...you aren't differing at all. Of course there's a greater energy with the faster projectile...no one said ther wasn't. Few just understand its effect. What Chuck posted explains it well.

[duffy4]

Originally Posted by Grizzly Adams

I guess, I beg to differ. One of my favorite experiments. Take two, one gallon plastic milk jugs, fill with water and cap. Shoot one with a .22 LR and the other with a .223. Then, tell me there isn't very much more energy transfer, in the latter.

Grizz

I think I see what you are getting at.

Chuck used to sign off with:
"Its holes that kill, not energy" or something like that.

I believe that the energy transfer of a bullet in the animals tissue (lungs/heart) has a lot to do with tissue destruction, bleeding and shock and death.

I have put holes through deer with a patched round ball from a muzzleloader and the deer eventually bleed to death. The same hit with a "high velocity expanding bullet" does more damage and kills faster.

I have shot a couple of deer with 250 grain bullets from a .35 whelen and the bullets went threw making holes without imparting much energy to the tissue. These deer died but not very fast or dramatically.

[Arn?Narn.]

well, ...

I'm not sure if it has to to do with the fact that I have shot a number of animals, assisted in autopsies, processed and examined way too much human tissue, or just the amount of science anatomy and physiology I have done,...but it sure comes logically to me that tissue damage due to energy transfer is minimal from a typical bullet at typical ft/lbs..

The prior is not me suggesting That I 'Know" better than anyone else,...simply stating that for some reason it is instilled in me that the logical conclusion is that energy transfer from bullets do not destroy much tissue...

Neither gels nor plastic jugs as mentioned above provide good evidence to support a claim that energy does collateral damge to tissue.

The human body (or whatever other animal) is an impressive shock absorber

A ridgid fixed membrane compartment (water jug) does not represent, even remotely, any component of tissue in the human body. The closest would probably be bone, but again, not at all similar.

A Gel, or at least the ones I am familar with, do noting more than show that there is radial energy released.
The gels themselves do not react as human tissue does.

Examine actual tissue... that's where real life evidence is.

[209x50]

Originally Posted by Arn?Narn.

well, ...

I'm not sure if it has to to do with the fact that I have shot a number of animals, assisted in autopsies, processed and examined way too much human tissue, or just the amount of science anatomy and physiology I have done,...but it sure comes logically to me that tissue damage due to energy transfer is minimal from a typical bullet at typical ft/lbs..

The prior is not me suggesting That I 'Know" better than anyone else,...simply stating that for some reason it is instilled in me that the logical conclusion is that energy transfer from bullets do not destroy much tissue...

Neither gels nor plastic jugs as mentioned above provide good evidence to support a claim that energy does collateral damge to tissue.

The human body (or whatever other animal) is an impressive shock absorber

A ridgid fixed membrane compartment (water jug) does not represent, even remotely, any component of tissue in the human body. The closest would probably be bone, but again, not at all similar.

A Gel, or at least the ones I am familar with, do noting more than show that there is radial energy released.
The gels themselves do not react as human tissue does.

Examine actual tissue... that's where real life evidence is.

Actually the gels do a remarkable job of imitating flesh in bullet impacts. The gel goes through the huge temporary wound expansion and yet returns to original shape like flesh. Clay and other media don't as pointed out in the article. The bullets expansion stages and fragmentation along the path are easily viewable. Damage done by fragmentation and the permanent wound cavity are all visible once the action stops. A lot of study went into designing ballistic gel for testing bullets and ordinance by people who wanted to study the effects of bullet trauma and learn from it to better help gunshoot victims. Nothing else comes close.