Stopping power is the supposed ability of a weapon — typically a ranged weapon such as a firearm — to incapacitate or immobilize a target (human or animal). Stopping power contrasts with lethality in that it pertains only to a weapon's ability to make the target cease action, regardless of whether or not death ultimately occurs. Which ammunition cartridges have the greatest stopping power is a much-debated topic. Stopping power is related to the physical properties and terminal behavior of the projectile (bullet, shot, or slug), the biology of the target, and the wound location, but the issue is complicated and not easily studied. Although higher-caliber ammunitions usually have greater muzzle energy and momentum and thus traditionally been widely associated with higher stopping power, the physics involved are multifactorial, with caliber, muzzle velocity, bullet mass, bullet shape and bullet material all contributing to the ballistics. Despite much disagreement, the most popular theory of stopping power is that it is usually caused not by the force of the bullet but by the wounding effects of the bullet, which are typically a rapid loss of blood causing a circulatory failure, which leads to impaired motor function and/or unconsciousness. The "Big Hole School" and the principles of penetration and permanent tissue damage are in line with this way of thinking. The other prevailing theories focus more on the energy of the bullet and its effects on the nervous system, including hydrostatic shock and energy transfer, which is similar to kinetic energy deposit.
History The concept of stopping power appeared in the late 19th century when colonial troops (including American troops in the Philippines during the Moro Rebellion, and British soldiers during the New Zealand Wars) at close quarters found that their pistols were not able to stop charging native tribesmen. This led to the introduction or reintroduction of larger caliber weapons (such as the older .45 Colt and the newly developed .45 ACP) capable of stopping opponents with a single round. During the Seymour Expedition in China, at one of the battles at Langfang, Chinese Boxers, armed with swords and spears, conducted a massed infantry charge against the forces of the Eight-Nation Alliance, who were equipped with rifles. At point-blank range, a British soldier had to fire four .303 Lee-Metford bullets into a Boxer before he stopped charging. U.S. Army officer Bowman McCalla reported that single rifle shots were not enough: multiple rifle shots were needed to halt a Boxer. Only machine guns were effective in immediately stopping the Boxers. In the Moro Rebellion, Moro Muslim Juramentados in suicide attacks continued to charge against American soldiers even after being shot. Panglima Hassan in the Hassan uprising had to be shot dozens of times before he died. This forced the Americans to phase out .38 Long Colt revolvers and start using .45 Colt against the Moros. British troops used expanding bullets during various conflicts in the Northwest Frontier in India, and the Mahdist War in Sudan. The British government voted against a prohibition on their use at the Hague Convention of 1899, although the prohibition only applied to international warfare. In response to addressing stopping power issues, the Mozambique drill was developed to maximize the likelihood of a target's quick incapacitation. "Manstopper" is an informal term used to refer to any combination of firearm and ammunition that can reliably incapacitate, or "stop", a human target immediately. For example, the .45 ACP round and the .357 Magnum round both have firm reputations as "manstoppers". Historically, one type of ammunition has had the specific tradename "Manstopper". Officially known as the Mk III cartridge, these were made to suit the British Webley .455 service revolver in the early 20th century. The ammunition used a 220-grain (14 g) cylindrical bullet with hemispherical depressions at both ends. The front acted as a hollow point deforming on impact while the base opened to seal the round in the barrel. It was introduced in 1898 for use against "savage foes", but fell quickly from favor due to concerns of breaching the Hague Convention's international laws on military ammunition, and was replaced in 1900 by re-issued Mk II pointed-bullet ammunition. Some sporting arms are also referred to as "stoppers" or "stopping rifles". These powerful arms are often used by game hunters (or their guides) for stopping a suddenly charging animal, like a buffalo or an elephant.
Dynamics of bullets
A bullet will destroy or damage any tissues which it penetrates, creating a wound channel. It will also cause nearby tissue to stretch and expand as it passes through tissue. These two effects are typically referred to as permanent cavity (the track left by the bullet as it penetrates flesh) and temporary cavity, which, as the name implies, is the temporary (instantaneous) displacement caused as the bullet travels through flesh, and is many times larger than the actual diameter of the bullet. These phenomena are unrelated to low-pressure cavitation in liquids. The degree to which permanent and temporary cavitation occurs is dependent on the mass, diameter, material, design and velocity of the bullet. 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 may crush only the tissue directly in front of the bullet. This type of bullet (monolithic-solid rifle bullet) is conducive to causing more temporary cavitation as the tissue flows around the bullet, resulting in a deep and narrow wound channel. A bullet constructed with a two diameter, hollow point ogive designed meplat and low-antimony lead-alloy core with a thin gilding metal jacket material will crush tissue in front and to the sides as the bullet expands. 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 wider wound channel. The exception to this general rule is non-expanding bullets which are long relative to their diameter. These tend to destabilize and yaw (tumble) soon after impact, increasing both temporary and permanent cavitation.
… excerpt ends here. Continue reading the full article.
