Stopping power is a colloquial term used to describe the ability of a weapon to stop the actions of an individual through a penetrating ballistic injury. A colloquialism is an expression not used in formal speech, writing or Paralinguistics. This term is not a euphemism for lethality; it refers only to a weapon's ability to incapacitate quickly, regardless of whether death ultimately results. A euphemism is a substitution of an agreeable or less offensive expression in place of one that may offend or suggest something unpleasant to the listener or in the case of doublespeak Lethality is a term designating the ability of a Weapon to kill Some theories of stopping power involve concepts such as "energy transfer" and "hydrostatic shock", although there is disagreement regarding the importance of these effects. In Physics, energy transfer describes the process of transferring Energy from one body to another The term hydrostatic shock describes the theory that a penetrating projectile produces remote wounding and incapacitating effects in living targets in addition to local effects in tissue Obviously, stopping power is related to the physical properties of the bullet and the effects it has on its target, but the issue is complicated and not easily studied. Critics contend that the importance of "one-shot stop" statistics is overstated, pointing out that most gun encounters do not involve a "shoot once and see how the target reacts" situation.

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 of the bullet which are typically a loss of blood, and with it, blood pressure. A rifle is a Firearm designed to be fired from the shoulder with a barrel that has a helical groove or pattern of grooves ("rifling" cut into the barrel walls Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells ��such as nutrients and oxygen—and transports Waste products Blood pressure is also the title of a short story by Damon Runyan in Guys and Dolls and Other Stories More immediate effects can result when a bullet damages the central nervous system such as the spine or brain. In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. In response to addressing stopping power issues, the Mozambique Drill was developed, to maximize the likelihood of a quick incapacitation of an attacker. The Mozambique Drill (also known as the Failure Drill, Rhodesian Drill or 2+1 Drill) instructs the shooter to place a Double-tap in the center

Contents 1 History 2 Dynamics of bullets 3 Physical effects 4 Neurological effects 5 Psychological effects 6 Industry penetration requirements 7 Overpenetration 8 Other hypotheses of stopping power 8.1 Hydrostatic shock 8.2 Energy transfer 8.2.1 Knockback 8.3 One-shot stop 8.4 Big Hole School 8.5 Other Contributing Factors 9 References 10 See also 11 External links

History

The concept of "stopping power" appeared in the late 19th Century when colonial troops (American in the Philippines, British in New Zealand) engaging in close action with native tribesmen found that their pistols were not able to stop charging warriors. The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar The United States of America —commonly referred to as the The Philippines ( Filipino: Pilipinas, officially known as the Republic of the Philippines (fil ''Republika ng Pilipinas'' RP The British Empire was the largest empire in history and for over a century was the foremost global power. New Zealand is an Island country in the south-western Pacific Ocean comprising two main landmasses (the North Island and the South Island According to the Random House Dictionary, the term warrior has two meanings This led to larger caliber weapons (such as the .45 ACP) being developed to stop opponents with a single round. (See Knockback)

Dynamics of bullets

A bullet will destroy or damage any tissues which it penetrates, creating a wound channel. A bullet is a solid Projectile propelled by a Firearm or Air gun and is normally made from metal (usually Lead) Tissue is a cellular organizational level intermediate between cells and a complete organism It will also cause nearby tissue to stretch and expand as it passes through tissue. These two effects are typically referred to as permanent cavitation (the hole left by the bullet) and temporary cavitation (the tissue displaced as the bullet passed).

The degree to which permanent and temporary cavitation occur is dependent on the weight, diameter, material, design and velocity of the bullet. Geometry, a diameter of a Circle is any straight Line segment that passes through the center of the circle and whose Endpoints are on the In Physics, velocity is defined as the rate of change of Position. This is because bullets crush tissue, and do not cut it. A bullet constructed with a half diameter ogive designed meplat and hard, solid copper alloy material will crush only the tissue directly in front of the bullet. An ogive ("Oh-jive" is a curved shape figure or feature Meplat is the technical term for the tip or nose of a Bullet. Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 This type of bullet (monolithic-solid rifle bullet) is conducive to cause more temporary cavitation as the tissue flows around the bullet, causing a deep and narrow wound channel. A bullet constructed with a two diameter, hollow point ogive designed meplat and low antimony lead core with a thin gilding metal jacket material will crush tissue in front and to the sides as the bullet expands. An ogive ("Oh-jive" is a curved shape figure or feature Antimony (IPA (Received Pronunciation, /ˈæntɪmoʊni/ (US is a Chemical element with the symbol Sb (stibium meaning "mark" and Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly Due to the energy expended in bullet expansion, velocity is lost more quickly. This type of bullet (hollow-point hand gun bullet) is conducive to causing more permanent cavitation as the tissue is crushed and accelerated into other tissues by the bullet, causing a shorter and more voluminous wound channel.

Bullets are constructed to behave in different ways, depending on the intended target. Different bullets are constructed variously to: not expand upon impact, expand upon impact at high velocity, expand upon impact, expand across a broad range of velocities, expand upon impact at low velocity, fragment upon impact, or disintegrate upon impact.

To control the expansion of a bullet, meplat design and materials are engineered. The meplat designs are: flat; round to pointed depending on the ogive; hollow pointed which can be large in diameter and shallow or narrow in diameter and deep and truncated which is a long narrow punched hole in the end of a monolithic-solid type bullet. The materials used to make bullets are: pure lead; alloyed lead for hardness; gilding metal jackets which is a copper alloy of nickel and zinc to promote higher velocities; pure copper; copper alloy of bronze and tungsten steel alloy inserts to promote weight. Gilding metal is a Copper Alloy, comprising 95% copper and 5% Zinc. Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Bronze is any of a broad range of Copper alloys, usually with Tin as the main additive but sometimes with other elements such as Phosphorus Tungsten (ˈtʌŋstən also known as wolfram (/ˈwʊlfrəm/ is a Chemical element that has the symbol W and Atomic number 74

Some bullets are constructed by bonding the lead core to the jacket to promote higher weight retention upon impact, causing a larger and deeper wound channel. Some bullets have a web in the center of the bullet to limit the expansion of the bullet while promoting penetration. Some bullets have dual cores to promote penetration.

Bullets that might be considered to have stopping power for dangerous large game animals are usually 11. 63 mm (. 458 caliber) and larger, including 12-gauge shotgun slugs. These bullets are monolithic-solids; full metal jacketed and tungsten steel insert. They are constructed to hold up during close range, high velocity impacts. These bullets are expected to impact and penetrate, and transfer energy to the surrounding tissues and vital organs through the entire length of a game animal’s body if need be.

Bullets with sufficient stopping power for humans are generally large caliber, 9. 07 mm (. 357 caliber) handgun bullets of hollow point design. The term caliber or calibre designates the interior Diameter of a tube or the exterior diameter of a wire or rod Pre-fragmented bullets such as Glaser Safety Slugs and Magsafe ammunition are designed to fragment into birdshot on impact with the target. Glaser Safety Slug Inc is a small American Ammunition company based in Sturgis South Dakota (the same location as Cor-Bon) A shotgun shell (shotshell is a self-contained cartridge loaded with shot or a slug designed to be fired from a Shotgun. This fragmentation is intended to create more trauma to the target, and also to reduce collateral damage caused from ricocheting or over-penetrating of the target and the surrounding environments such as walls.

Physical effects

Permanent and temporary cavitation cause very different biological effects. The effects of a permanent cavity are fairly obvious. A hole through the heart will cause loss of pumping efficiency, loss of blood, and eventual cardiac arrest. The heart is a muscular organ in all Vertebrates responsible for pumping Blood through the Blood vessels by repeated rhythmic A cardiac arrest, also known as cardiorespiratory arrest, cardiopulmonary arrest or circulatory arrest, is the abrupt cessation of normal circulation of A hole through the brain can cause instant unconsciousness and will likely kill the recipient. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain See also Unconscious mind. Unconsciousness, more appropriately referred to as loss of Consciousness or lack of consciousness is A hole through an arm or leg which hits only muscle, however, will cause a great deal of pain but is unlikely to be fatal, unless one of the large blood vessels (femoral or brachial arteries, for example) is also severed in the process. Muscle (from Latin musculus, diminutive of mus "mouse" is contractile tissue of the body and is derived from the The brachial artery is the major Blood vessel of the upper arm

The effects of temporary cavitation are less well understood, due to a lack of a test material identical to living tissue. Studies on the effects of bullets typically are based on experiments using ballistic gelatin, in which temporary cavitation causes radial tears where the gelatin was stretched. Ballistic gelatin is a solution of Gelatin powder in Water. Ballistic gelatin closely simulates the Density and Viscosity of human and Although such tears are visually engaging, some animal tissues, (other than bone or liver) are more elastic than gelatin. A material is said to be elastic if it deforms under stress (e In most cases, temporary cavitation is unlikely to cause anything more than a slight bruise. Some speculation states that nerve bundles can be damaged by temporary cavitation, creating a stunning effect, but this has not been confirmed. A nerve is an enclosed cable-like bundle of peripheral Axons (the long slender projections of Neurons.

One exception to this is when a very powerful temporary cavity intersects with the spine. In Human anatomy, the vertebral column ( backbone or spine) is a column of 34 Vertebrae the Sacrum, Intervertebral In this case, the resulting blunt trauma can slam the vertebrae together hard enough to either sever the spinal cord, or damage it enough to knock out, stun, or paralyze the target. Treatment of physical trauma is described here and in First aid. A vertebra (plural vertebrae) is an individual Irregular bone in the spinal or Vertebral column ( aka ischis a flexuous and flexible column Paralysed redirects here For other uses see xx Paralysed (disambiguation Paralysis is the complete loss of Muscle function For instance, in the shootout between eight FBI agents and two bank robbers on April 11, 1986 in Miami, Florida, (see FBI Miami shootout, 1986) Special Agent Gordon McNeill was struck in the neck by a high-velocity . Events 491 - Flavius Anastasius becomes Byzantine Emperor, with the name of Anastasius I. Year 1986 ( MCMLXXXVI) was a Common year starting on Wednesday (link displays 1986 Gregorian calendar) Florida ( is a state located in the southeastern region of the United States, bordering Alabama to the northwest and Georgia to the The FBI Miami shootout was a gun battle that occurred on April 11, 1986 in Miami, Florida between multiple FBI agents and two 223 bullet fired by Michael Platt. While the bullet did not directly contact the spine, and the wound incurred was not ultimately fatal, the temporary cavitation was sufficient to render SA McNeill paralyzed for several hours.

Temporary cavitation can also cause the tearing of tissues if a very large amount of force is involved. The tensile strength of muscle ranges roughly from 1 to 4 MPa (145 to 580 lbf/in²), and minimal damage will result if the pressure exerted by the temporary cavitation is below this. Gelatin and other less elastic media have much lower tensile strengths, thus they exhibit more damage after being struck with the same amount of force. At typical handgun velocities, bullets will create temporary cavities with much less than 1 MPa of pressure, and thus are incapable of causing damage to elastic tissues which they do not directly contact.

High velocity fragmentation can also increase the effect of temporary cavitation. The fragments sheared from the bullet cause many small permanent cavities around the main entry point. The main mass of the bullet can then cause a truly massive amount of tearing as the perforated tissue is stretched.

Whether a person or animal will be incapacitated (i. e. 'stopped') when shot depends on a large number of factors including physical, physiological, and psychological effects.

Neurological effects

The only way to immediately incapacitate a person or other animal is to damage or disrupt their central nervous system (CNS) to the point of becoming paralyzed, losing consciousness, or dying. In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. Bullets can achieve this directly or indirectly. If a bullet causes sufficient damage to the brain or spinal cord, immediate loss of consciousness or paralysis, respectively, can result. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain The spinal cord is a long thin tubular bundle of Nerves that is an extension of the Central nervous system from the brain and is enclosed in and protected However, these targets are relatively small and mobile, making them extremely difficult to hit even under optimal circumstances.

Bullets can indirectly disrupt the CNS by damaging the cardiovascular system so that it can no longer provide enough oxygen to the brain to sustain consciousness. This can be the result of bleeding from a perforation of a large blood vessel or blood-bearing organ, or the result of damage to the lungs or airway. Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells ��such as nutrients and oxygen—and transports Waste products If blood flow is completely cut off from the brain, a human still has enough oxygenated blood in their brain for 10 seconds of willful action, though with rapidly decreasing effectiveness as the victim begins to lose consciousness.

Unless a bullet directly damages or disrupts the central nervous system, a person or animal will not be instantly and completely incapacitated by physiological damage. However, bullets can cause other disabling injuries that prevent specific actions (a person shot in the femur cannot walk) and the physiological pain response from severe injuries will temporarily disable most individuals.

A number of papers in the peer-reviewed journals suggest ballistic pressure wave effects on wounding and incapacitation, including remote neural effects. ^{[1][2][2][3][4][5][6][7][8]} These papers are mainly concerned with velocities of rifle bullets, but the energy transfer and pressure waves produced are within the regime of pistol bullets.

Recent work by Courtney and Courtney provides compelling support for the role of a ballistic pressure wave in creating remote neural effects leading to incapacitation and injury. ^{[9][10][11][12] [13]}

This work builds upon the earlier works of Suneson et al. where the researchers implanted high-speed pressure transducers into the brain of pigs and demonstrated that a significant pressure wave reaches the brain of pigs shot in the thigh. ^[14][1] These scientists observed neural damage in the brain caused by the distant effects of the ballistic pressure wave originating in the thigh.

The results of Suneson et al. were confirmed and expanded upon by a later experiment in dogs^[2] which "confirmed that distant effect exists in the central nervous system after a high-energy missile impact to an extremity. A high-frequency oscillating pressure wave with large amplitude and short duration was found in the brain after the extremity impact of a high-energy missile . . . " Wang et al. observed significant damage in both the hypothalamus and hippocampus regions of the brain due to remote effects of the ballistic pressure wave.

Psychological effects

Emotional shock, terror, or surprise can cause a person to faint, surrender, or flee when shot or shot at. Emotional fainting is the likely reason for most "one-shot stops", and not an intrinsic effectiveness quality of any firearm or bullet; there are many documented instances where suspects have instantly dropped unconscious when the bullet only hit an extremity, or even completely missed. Additionally, the muzzle blast and flash from many firearms are substantial and can cause disorientation, dazzling, and stunning effects; flashbangs (stun grenades) and other less-lethal "distraction devices" rely exclusively on these effects.

Pain is another psychological factor, and can be enough to dissuade a person from continuing their actions. Pain, in the sense of physical pain, is a typical sensory experience that may be described as the unpleasant awareness of a noxious stimulus or bodily harm

Temporary cavitation can emphasize the impact of a bullet, since the resulting tissue compression is identical to simple blunt force trauma. It's easier for someone to feel when they been shot if there is considerable temporary cavitation, and this can contribute to either psychological factor of incapacitation.

However, if a person is sufficiently enraged, determined, or intoxicated they can simply shrug off the psychological effects of being shot; therefore, such effects are not as reliable as physiological effects at stopping people. Rage, in Psychiatry, is a mental state that is one extreme of the intensity spectrum of Anger. Intoxication is the state of being affected by one or more psychoactive drugs. Animals will not faint or surrender if injured, though they may become frightened by the loud noise and pain of being shot, so psychological mechanisms are generally less effective against non-humans.

Industry penetration requirements

According to Dr. Martin Fackler and the IWBA, between 12. 5 and 14 inches (318 and 356 mm) of penetration in calibrated tissue simulant is optimal performance for a bullet which is meant to be used defensively, against a human adversary. They also believe that penetration is one of the most important factors when choosing a bullet (and that the number one factor is shot placement); if the bullet penetrates less than their guidelines, it is inadequate, and if it penetrates more, it is still satisfactory though not optimal. The FBI's penetration requirement is very similar at 12 to 18 inches (305 to 457 mm).

A penetration depth of 12. 5 to 14 inches (318 and 356 mm) may seem excessive, but a bullet sheds velocity--and crushes a narrower hole--as it penetrates deeper, while losing velocity, so the bullet might be crushing a very small amount of tissue (simulating an "ice pick" injury) during its last two or three inches of travel, giving only between 9. 5 and 12 inches of effective wide-area penetration. Also, skin is elastic and tough enough that it can cause a bullet to be retained in the body, even if the bullet had a relatively high velocity when it hit the skin. About 250 ft/s (76 m/s) velocity is required for an expanded hollowpoint bullet to puncture skin 50% of the time.

The IWBA's and FBI's penetration guidelines are to ensure that the bullet can reach a vital structure from most angles, while retaining enough velocity to generate a large diameter hole through tissue. An extreme example where penetration would be important is if the bullet first had to enter and then exit an outstretched arm before impacting the torso. A bullet with low penetration might embed itself in the arm whereas a higher penetrating bullet would penetrate the arm then enter the thorax where it would have a chance of hitting a vital organ.

Overpenetration

Overpenetration is often emphasized by those that prefer shallow-penetrating "rapid energy transfer" bullets. Tests have shown that human skin, on the entry side, can resist penetration as much as 2" (5 cm) of muscle, and skin on the exit side can be the equivalent of up to 4 in (10 cm). A bullet would need to penetrate greater than approximately 15 inches (38 cm) of tissue simulant to have a chance to completely perforate a 9" (23 cm) thick torso, and would need to penetrate more than 17 inches (43 cm) to actually pose a serious threat to people downrange.

Even if the bullet does completely penetrate a person, it will have a very reduced velocity and probably will no longer be ballistically stable. Missing the intended target altogether, hence leaving a full velocity bullet to harm whatever is in its path, is a much greater threat.

A hit on a less dense peripheral body area, such as a limb, does present a more serious risk of overpenetration however. Penetration of walls and other cover is also a consideration for police and urban use.

According to NYPD SOP-9 (Standard Operating Procedure #9) data, in the year 2000, only 9% of shots fired by officers engaged in gunfights actually hit perpetrators at which they were fired. 2000 ( MM) was a Leap year that started on Saturday of the Common Era, in accordance with the Gregorian calendar. In the same year, there were a total of 129 "shooting incidents" (including non-gunfights, such as officers firing at aggressive dogs, unarmed or fleeing perpetrators, etc. ), 471 total shots fired by officers, 367 shots fired at perpetrators, and 58 total hits on perpetrators by police. So, when non-gunfight shooting data is added, the rate at which police hit what they aim at in real life situations is typically only 15. 8%.

A study done by the FBI found that the .223 Remington from a rifle had a smaller chance of over-penetration than the 9 mm Luger handgun round. The 9x19mm Parabellum is a pistol cartridge introduced in 1902 by the German weapons manufacturer Deutsche Waffen und Munitionsfabriken (DWM for their ^[15]

Other hypotheses of stopping power

These hypotheses are a matter of some debate ^[9] among scientists in the field:

Hydrostatic shock

Hydrostatic shock is a theory of terminal ballistics that wounding effects are created by a shock wave in the tissues of the target. The term hydrostatic shock describes the theory that a penetrating projectile produces remote wounding and incapacitating effects in living targets in addition to local effects in tissue Terminal ballistics, a sub-field of Ballistics, is the study of the behavior of a Projectile when it hits its target Evidence of such shock can be seen in ultra-high-speed images of supersonic bullets passing through various objects such as fruit; the fruit explodes due to the shock waves caused by the bullet passing through at high speed. This theory however is only applicable to high-speed ammunition such as rifle bullets; handgun ammunition provides insufficient speed and energy to duplicate these effects. "Hydra-Shock" handgun ammunition is therefore technically a misnomer; a bullet so named achieves its wounding capacity through expansion, ensuring maximum energy transfer and a larger permanent cavity than a nonexpanding bullet. .

Energy transfer

The energy transfer hypotheses states that the more energy that is transferred to the target, the greater the damage that is caused. In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός

This theory is frequently referred to by Kennedy assassination theories, who cite the Zapruder film, which shows Kennedy's head recoiling backwards from a shot, as evidence that therefore, that shot must have been fired from in front of the limousine rather than from behind, where Lee Harvey Oswald was claimed to be firing from the Texas School Book Depository, implying a second assassin. There are many conspiracy theories regarding the '''assassination of United States President John F The Zapruder film is a silent 8 mm color home movie of the presidential motorcade of John F Lee Harvey Oswald (October 18 1939 &ndash November 24 1963 was according to three United States government investigations the assassin of U The Texas School Book Depository (now the Dallas County Administration Building) is the former name of a seven-floor building located on Dealey Plaza in downtown However, it has been repeatedly demonstrated, most recently to a large television audience by Penn and Teller on May 9, 2005 on their Showtime network program, Bullshit!, that when a simplified physical model of a brain inside a skull, composed of a melon wrapped with strapping tape, is shot in a similar fashion, the melon recoils backwards, towards the gun; evidence that the actual transfer of energy from a bullet passing through a complex object is much more complex than simple mathematical models based on oversimplified physical assumptions can predict, a priori. Penn & Teller ( Penn Fraser Jillette and Teller) are Las Vegas headliners whose act is an amalgam of illusion and Comedy. Events 1457 BC - Battle of Megiddo (15th century BC between Thutmose III and a large Canaanite coalition under the King of Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. Showtime is a subscription television Brand used by a number of channels and platforms around the world but primarily refers to a group of channels in the United Melon is a term used for various members of the Cucurbitaceae family with fleshy fruit

However, it remains a general physical principle, that when a volume of energy is transferred from one medium to another, the greater the volume of energy, the greater the destructive potential.

In ballistics, energy is a function of velocity and mass. Generally speaking, bullets which impact a target with greater energy cause greater damage. A bullet with too little energy might not penetrate the target - although in the case of a living target they may suffer blunt force trauma, possibly resulting in internal injury solely through the force of the impact.

Overpenetration is detrimental to stopping power with regards to energy since a bullet that passes through the target has not completely shed all of its stored energy. However, the increased tissue damage as well as the creation of an exit wound (and increased blood loss) resulting from a bullet passing through a person also affect whether the target is likely to be incapacitated. Bullets that pass out of the body may still injure people nearby.

Rifles commonly propel bullets to speeds of at at least 2-3 times the velocity of the most powerful pistols. Such bullets have more kinetic energy (kinetic energy is proportional to the square of the speed). Bullets not intended to expand such as the 5.56 x 45 mm NATO, M855 Ball Round, may cause much more tissue damage as a result, than of expansion or fragmentation of a bullet at handgun velocities. 556x45mm NATO, standardized under STANAG 4172 is a Rifle cartridge. 556x45mm NATO, standardized under STANAG 4172 is a Rifle cartridge.

As discussed above, there are many factors that affect "stopping power. " Energy transfer is undeniably related to destructive potential; however, the importance of energy transfer in determining the stopping power of bullets (when compared to other factors like location of the wound and bullet size) is not a topic of agreement.

It is a general principal of physics that the force between the bullet and tissue is equal to the bullet's local rate of energy loss, dE/dx (the first derivative of the bullets kinetic energy with respect to position). The ballistic pressure wave is proportional to this retarding force (Courtney and Courtney), and this retarding force is also the origin of both temporary cavitation and prompt damage (CE Peters).

Knockback

The idea of "knockback" is a subset or simplification of energy transfer theory, and states that a bullet of sufficient caliber at sufficient speed which transfers all its energy to a subject has enough force, by sheer momentum of the bullet, to stop forward momentum of an attacker and knock them backwards or downwards. The idea was first widely expounded in ballistics discussions during American involvement in Philippine insurrections and, simultaneously, in British involvement in the Caribbean, when front-line reports stated that the . 38 caliber revolvers carried by U. S. and British soldiers were incapable of bringing down a charging warrior. Thus, in the early 1900s, the U. S. adopted the .45ACP cartridge in what was to become the M1911A pistol and the British adopted the .455 Webley caliber cartridge in the Webley Revolver. The M1911 is a single-action, Semi-automatic pistol ( Handgun) chambered for the. The Webley Revolver (also known as the Webley Break-Top Revolver or Webley The larger cartridges were chosen largely due to the Big Hole Theory (a larger hole does more damage), but the common interpretation was that these were changes from a light, deeply-penetrating bullet to a larger, heavier "manstopper" bullet.

Though popularized in television and movies, and commonly referred to as "true stopping power" by novice or uneducated proponents of large powerful calibers such as .44 Magnum, the effect of knockback from a handgun and indeed most personal weapons is largely a myth. Because of Newton's Third Law, "for every action, there is an equal and opposite reaction", a handgun bullet propelled with sufficient force to arrest forward momentum or impart backward momentum in a human-sized target mass would impart an equal force to the shooter, knocking both the shooter AND target to the ground. Newton's laws of motion are three Physical laws which provide relationships between the Forces acting on a body and the motion of the The force of the so-called "manstopper" .45ACP bullet is, in reality, comparable to the force imparted by a 1 kg (2. 2 pound) mass dropped from a height of 3. 47 m (11. 4 feet) onto a surface. ^[16] Such a force is simply incapable of arresting a running target's forward momentum. In addition, bullets are designed to penetrate instead of strike a blunt force blow, because, in penetrating, more severe tissue damage is done. A bullet with sufficient energy to knock down an assailant, such as a high-speed rifle bullet, would be more likely to instead pass straight through, while not transferring the full energy (in fact only a very small percentage of the full energy) of the bullet to the victim.

The "knockback" effect is however commonly "seen" in real-life shootings, and can be explained by physiological and psychological means. Humans encountering a physical hit, be it a punch or a bullet, are conditioned to absorb the blow by moving in the same direction as the force. The physical effect against a non-penetrating weapon is to reduce the force felt by the blow, and in addition, retreating from an attack increases the distance such an attack must cover, which in the case of non-projectile weapons such as fists or a knife, places the target out of range of further attack. In addition, there is thought that modern civilization, with far greater separation by most individuals from violence, hunting, and combat, may lead to normal individuals simply recoiling, buckling, or falling backward when hit by a bullet, even when in pure physiological terms they are perfectly capable of continuing to charge.

Although knockback is not possible with a handgun bullet, it can be an actual effect occurring in reaction to being hit by a massive slug, such as a rubber bullet or sandbag fired from a shotgun. A shotgun (also known as a scattergun) is a Firearm that is usually designed to be fired from the shoulder which uses the energy of a fixed shell to fire a number The dynamics of a slug round are quite different than penetrating bullets; the projectile is here designed NOT to penetrate but instead to strike a hard, blunt force blow, and as the power of a shotgun cartridge is greater than practically any production handgun cartridge, the force imparted is comparable to a hard punch and is capable, by sheer physics, of doubling up, hence knocking down, someone.

One-shot stop

This hypothesis, promoted by Evan P. Marshall, is based solely on statistics, intended to be used as a unit of measurement and not as a tactical philosophy, as mistakenly believed by some. It considers the history of shooting incidents for a given factory ammunition load, and compiles the percentage of "one-shot-stops" achieved with each specific ammunition load. That percentage is then intended to be used with other information to help predict the effectiveness of that load getting a "one-shot-stop. " For example, if an ammunition load is used in 10 torso shootings, incapacitating all but two with one shot, the "one-shot-stop" percentage for the total sample would be 80%.

Some argue that this hypothesis ignores any inherent selection bias. Selection bias is a distortion of evidence or data that arises from the way that the data are collected For example, high-velocity 9 mm hollow point rounds appear to have the highest percentage of one-shot stops. The 9x19mm Parabellum is a pistol cartridge introduced in 1902 by the German weapons manufacturer Deutsche Waffen und Munitionsfabriken (DWM for their A hollow point is a Bullet that has a pit or hollowed out shape in its tip generally intended to cause the bullet to expand upon entering a target in order to decrease Rather than identifying this as an inherent property of the firearm/bullet combination, the situations where these have occurred need to be considered. The 9 mm has been the predominantly-used caliber of many police departments, so many of these one-shot-stops were probably made by well-trained police officers, where accurate placement would be a contributory factor. However, Marshall's database of "one-shot-stops" does include shootings from law enforcement agencies, private citizens, and criminals alike.

Critics of this theory point out that bullet placement is a very significant factor, but is only generally used in such one-shot-stop calculations, covering shots to the torso.

Some CCW holders in the United States have elected since 2006 to switch from carrying hollow-point bullets and especially 10 mm caliber weapons with perceived higher one-shot stopping power to instead favor carrying smaller caliber weapons after the conviction of retired school teacher Harold Fish in Arizona for second degree murder during a self-defense shooting. In the United States, carrying a concealed weapon ( CCW, also known as concealed carry) is the legal authorization for private citizens to carry His conviction for killing a homeless man with a history of mental instability who attacked him while hiking on a remote trail was obtained through a jury trial by stressing Fish overreacted through choosing to use the increased stopping power of 10 mm hollow point bullets. A hollow point is a Bullet that has a pit or hollowed out shape in its tip generally intended to cause the bullet to expand upon entering a target in order to decrease State law in Arizona has subsequently been changed, such that the state now has the burden to prove that a self defense shooting was not in self defense, whereas the burden previously before the Fish incident was that the shooter on trial had to prove that the shooting was in fact done in self defense. Meanwhile, many CCW holders have elected to switch to carrying handguns loaded with FMJ bullets in calibers smaller than 10 mm. A full metal jacket (or FMJ) is a Bullet encased in a shell of Copper Alloy (such as Gilding metal or Cupronickel) or a A choice often advocated for selecting the correct stopping power in CCW training classes is to select to use the exact same type of bullets (FMJ or hollow point), in the exact same caliber that are used by the local police, to avoid being accused of overreacting during any self defense post-incident trial. ^[17][18]

Big Hole School

This school of thought says that the bigger the hole in the target the higher the rate of bleed-out and thus the higher the rate of the "magical" one shot kill. In this theory, the bullet does not pass entirely through the body so that it incorporates the energy transfer and the overpenetration ideals. The people that like this theory cite the . 40 S&W round to be the best bet, arguing that it has a better ballistic profile than the . 45, with more stopping power than a 9x19mm Parabellum.

The theory centers on the "permanent cavitation" element of a handgun wound; a big hole damages more tissue. It is therefore valid to a point, but penetration is also important, as a large bullet that doesn't penetrate will be less likely to strike vital blood vessels and blood-carrying organs such as the heart and liver, while a smaller bullet that penetrates deep enough to strike these organs or vessels will cause faster bleed-out through a smaller hole. The ideal may therefore be a combination; a large bullet that penetrates deeply, which can be achieved with a larger, slower non-expanding bullet, or a smaller, faster expanding bullet such as a hollow point.

Other Contributing Factors

As it has been touched on previously, drug and/or alcohol levels within the body, body mass index, mental illness, motivation levels, body part strike (i. e. "armpit hold") all these things and more contribute to the concept of what round will possess true stopping power during which situation.

References

See also

• Expanding bullet
• Terminal ballistics
• Hydrostatic shock

External links

• Wound Ballistics
• Reality of the Street? A Practical Analysis of Offender Gunshot Wound Reaction for Law Enforcement
• Handgun Wounding Factors and Effectiveness
• Ballistic gelatin testing done by "GoldenLoki"
• Several journal articles by Martin Fackler, M.D.
• What We Didn't Know Hurt Us (PDF)
• One Shot Drops - Surviving the Myth
• Ammunition for the Self-Defense Handgun - anonymous
• Terminal effects of the Mk 7 .303 British cartridge
• Discrepancies in the Marshall & Sanow "Data Base": An Evaluation Over Time

Terminal ballistics, a sub-field of Ballistics, is the study of the behavior of a Projectile when it hits its target The term hydrostatic shock describes the theory that a penetrating projectile produces remote wounding and incapacitating effects in living targets in addition to local effects in tissue

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