HOME

TheInfoList



OR:

A bullet is a
kinetic projectile A kinetic energy weapon (also known as kinetic weapon, kinetic energy warhead, kinetic warhead, kinetic projectile, kinetic kill vehicle) is a weapon based solely on a projectile's kinetic energy instead of an explosive or any other kind of pay ...
, a component of firearm
ammunition Ammunition (informally ammo) is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons (e.g., bombs, missiles, grenades, land mines) and the component parts of other weapo ...
that is shot from a gun barrel. Bullets are made of a variety of materials, such as copper, lead, steel, polymer, rubber and even wax. Bullets are made in various shapes and constructions (depending on the intended applications), including specialized functions such as
hunting Hunting is the human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products ( fur/ hide, bone/ tusks, horn/ a ...
,
target shooting Shooting sports is a group of competitive and recreational sporting activities involving proficiency tests of accuracy, precision and speed in shooting — the art of using ranged weapons, mainly small arms ( firearms and airguns, in forms s ...
, training and combat. Bullets are often tapered, making them more
aerodynamic Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
. Bullet sizes are expressed by their weights and diameters (referred to as " calibers") in both imperial and metric measurement systems. For example: 55
grain A grain is a small, hard, dry fruit ( caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legu ...
.223 caliber bullets are of the same weight and caliber as 3.56 gram 5.56mm caliber bullets. Bullets do not normally contain
explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...
s but strike or damage the intended target by transferring
kinetic energy In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its a ...
upon impact and penetration. Bullets shot by firearms can be used for
target practice In the military and in shooting, target practice are exercises in which weapons are shot at a target. The purpose of such exercises is to improve the aim or the weapons handling expertise of the person firing the weapon. Targets being shot a ...
or
hunting Hunting is the human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products ( fur/ hide, bone/ tusks, horn/ a ...
.


Description

The term ''bullet'' is from Middle French, originating as the
diminutive A diminutive is a root word that has been modified to convey a slighter degree of its root meaning, either to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment. A ( abbreviated ) is a word-form ...
of the word ''boulle'' (''boullet''), which means "small ball". Bullets are available singly (as in muzzle-loading and cap and ball firearms) but are more often packaged with propellant as a cartridge ("round" of ammunition) consisting of the ''bullet'' (i.e., the projectile), the ''case'' (which holds everything together), the ''
propellant A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the ...
'' (which provides the majority of the energy to launch the projectile), and the '' primer'' (which ignites the propellant). Cartridges, in turn, may be held in a ''magazine'' or a ''belt'' (for rapid-fire automatic firearms). Although the word ''bullet'' is often used in colloquial language to refer to a cartridge round, a bullet is ''not'' a cartridge but rather a component of one. This use of the term ''bullet'' (when intending to describe a cartridge) often leads to confusion when a cartridge and all its components is specifically being referenced. Bullets used in many cartridges are fired at
muzzle velocities Muzzle velocity is the speed of a projectile (bullet, pellet, slug, ball/shots or shell) with respect to the muzzle at the moment it leaves the end of a gun's barrel (i.e. the muzzle). Firearm muzzle velocities range from approximately to ...
faster than the
speed of sound The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At , the speed of sound in air is about , or one kilometre in or one mile in . It depends strongly on temperature as ...
—about in dry air at —and thus can travel a substantial distance to a target before a nearby observer hears the sound of the shot. The sound of gunfire (i.e. the "muzzle report") is often accompanied with a loud
bullwhip A bullwhip is a single-tailed whip, usually made of braided leather or nylon, designed as a tool for working with livestock or competition. Bullwhips are pastoral tools, traditionally used to control livestock in open country. A bullwhip's len ...
-like crack as the
supersonic Supersonic speed is the speed of an object that exceeds the speed of sound (Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times ...
bullet pierces through the air, creating a
sonic boom A sonic boom is a sound associated with shock waves created when an object travels through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding similar to an explosion or a thunderclap to t ...
. Bullet speeds at various stages of flight depend on intrinsic factors such as
sectional density Sectional density (often abbreviated SD) is the ratio of an object's mass to its cross sectional area with respect to a given axis. It conveys how well an object's mass is distributed (by its shape) to overcome resistance along that axis. Secti ...
, aerodynamic profile and
ballistic coefficient In ballistics, the ballistic coefficient (BC, ''C'') of a body is a measure of its ability to overcome air resistance in flight. It is inversely proportional to the negative acceleration: a high number indicates a low negative acceleration—the ...
, as well as extrinsic factors such as
barometric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibar ...
, humidity, air temperature and wind speed. Subsonic cartridges fire bullets slower than the speed of sound, so there are no sonic booms. This means that a subsonic cartridge, such as
.45 ACP The .45 ACP ( Automatic Colt Pistol) or .45 Auto (11.43×23mm) is a rimless straight-walled handgun cartridge designed by John Moses Browning in 1904, for use in his prototype Colt semi-automatic pistol. After successful military trials, it ...
, can be substantially quieter than a supersonic cartridge, such as the
.223 Remington The .223 Remington (designated as the 223 Remington by the SAAMI and 223 Rem by the CIP) is a rimless, bottlenecked rifle cartridge. It was developed in 1957 by Remington Arms and Fairchild Industries for the U.S. Continental Army Command ...
, even without the use of a suppressor. Bullets shot by firearms can be used for
target practice In the military and in shooting, target practice are exercises in which weapons are shot at a target. The purpose of such exercises is to improve the aim or the weapons handling expertise of the person firing the weapon. Targets being shot a ...
or to injure or kill animals or people. Death can be by blood loss or damage to vital organs, or even
asphyxiation Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can ...
if blood enters the lungs. Bullets are not the only projectiles shot from firearm-like equipment: BBs are shot from BB guns, airsoft pellets are shot by airsoft guns, paintballs are shot by paintball markers, and small rocks can be hurtled from slingshots. There are also flare guns, potato guns (and spud guns),
tasers A taser is an electroshock weapon used to incapacitate people, allowing them to be approached and handled in an unresisting and thus safe manner. It is sold by Axon, formerly TASER International. It fires two small barbed darts intended to ...
, bean bag rounds,
grenade launchers A grenade launcher is a weapon that fires a specially-designed large-caliber projectile, often with an explosive, smoke or gas warhead. Today, the term generally refers to a class of dedicated firearms firing unitary grenade cartridges. The most ...
, flash bangs,
tear gas Tear gas, also known as a lachrymator agent or lachrymator (), sometimes colloquially known as "mace" after the early commercial aerosol, is a chemical weapon that stimulates the nerves of the lacrimal gland in the eye to produce tears. In ...
, RPGs, and missile launchers. Bullet sizes are expressed by their weights and diameters (referred to as " calibers") in both imperial and metric measurement systems. For example: 55
grain A grain is a small, hard, dry fruit ( caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legu ...
.223 caliber bullets are of the same weight and caliber as 3.56 gram 5.56mm caliber bullets.


History

The first true gun evolved in China from the fire lance (a bamboo tube that fired porcelain shrapnel) with the invention of the metal hand cannon sometime around 1288, which the
Yuan dynasty The Yuan dynasty (), officially the Great Yuan (; xng, , , literally "Great Yuan State"), was a Mongols, Mongol-led Dynasties in Chinese history, imperial dynasty of China and a successor state to the Mongol Empire after Division of the M ...
used to win a decisive victory against Mongolian rebels. The artillery
cannon A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder duri ...
appeared in 1326 and the European hand cannon in 1364. Early projectiles were made of stone. Eventually it was discovered that stone would not penetrate stone fortifications, which led to the use of denser materials as projectiles. Hand cannon projectiles developed in a similar manner. The first recorded instance of a metal ball from a hand cannon penetrating armor was in 1425. Shot retrieved from the wreck of the ''
Mary Rose The ''Mary Rose'' (launched 1511) is a carrack-type warship of the English Tudor navy of King Henry VIII. She served for 33 years in several wars against France, Scotland, and Brittany. After being substantially rebuilt in 1536, she saw her ...
'' (sunk in 1545, raised in 1982) are of different sizes, and some are stone while others are cast iron. The development of the hand
culverin A culverin was initially an ancestor of the hand-held arquebus, but later was used to describe a type of medieval and Renaissance cannon. The term is derived from the French "''couleuvrine''" (from ''couleuvre'' "grass snake", following the Lat ...
and
matchlock A matchlock or firelock is a historical type of firearm wherein the gunpowder is ignited by a burning piece of rope that is touched to the gunpowder by a mechanism that the musketeer activates by pulling a lever or trigger with his finger. Befo ...
arquebus An arquebus ( ) is a form of long gun that appeared in Europe and the Ottoman Empire during the 15th century. An infantryman armed with an arquebus is called an arquebusier. Although the term ''arquebus'', derived from the Dutch word ''Haakbu ...
brought about the use of
cast Cast may refer to: Music * Cast (band), an English alternative rock band * Cast (Mexican band), a progressive Mexican rock band * The Cast, a Scottish musical duo: Mairi Campbell and Dave Francis * ''Cast'', a 2012 album by Trespassers William ...
lead balls as projectiles. The original round
musket A musket is a muzzle-loaded long gun that appeared as a smoothbore weapon in the early 16th century, at first as a heavier variant of the arquebus, capable of penetrating plate armour. By the mid-16th century, this type of musket graduall ...
ball was smaller than the bore of the barrel. At first it was loaded into the barrel just resting upon the powder. Later, some sort of material was used as a wadding between the ball and the powder as well as over the ball to keep it in place, it held the bullet firmly in the barrel and against the powder. (Bullets not firmly set on the powder risked exploding the barrel, with the condition known as a "short start".) The loading of muskets was therefore easy with the old smooth-bore Brown Bess and similar military muskets. The original muzzle-loading rifle, however, was loaded with a piece of leather or cloth wrapped around the ball, to allow the ball to engage the grooves in the barrel. Loading was a bit more difficult, particularly when the bore of the barrel was fouled from previous firings. For this reason, and because rifles were not often fitted for bayonets, early rifles were rarely used for military purposes, compared to muskets. There was a distinct change in the shape and function of the bullet during the first half of the 19th century. In 1826,
Henri-Gustave Delvigne Henri-Gustave Delvigne (April 10, 1800 in Hamburg – October 18, 1876 in Toulon) was a French soldier and inventor. He became a captain in the French infantry service, from which he resigned on the outbreak of the 1830 July Revolution. Del ...
, a French
infantry Infantry is a military specialization which engages in ground combat on foot. Infantry generally consists of light infantry, mountain infantry, motorized infantry & mechanized infantry, airborne infantry, air assault infantry, and m ...
officer, invented a breech with abrupt shoulders on which a spherical bullet was rammed down until it caught the
rifling In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize ...
grooves. Delvigne's method, however, deformed the bullet and was inaccurate. In 1855 a detachment of 1st U.S. Dragoons, while on patrol, traded lead for gold bullets with Pima Indians along the California–Arizona border. "The use of gold bullets by Indians is confirmed by Aubry in a journey across central Arizona. ''"The Indians use gold bullets for their guns. They are of different sizes and each Indian has a pouch of them. We saw an Indian load his gun with one large and three small gold bullets to shoot a rabbit."'' Square bullets have origins that almost pre-date civilization and were used in slings. They were typically made out of copper or lead. The most notable use of square bullet designs was by James Puckle and Kyle Tunis who patented them, where they were briefly used in one version of the Puckle gun. The early use of these in the
black-powder Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate (saltpeter). Th ...
era was soon discontinued because of the irregular and unpredictable flight patterns.


Pointed bullets

Delvigne continued to develop bullet design and by 1830 had started to develop cylindro-conical bullets. His bullet designs were improved by Francois Tamisier with the addition of "ball grooves" which are known as " cannelures", which moved the resistance of air behind the center of gravity of the bullet. Tamisier also developed progressive rifling: the rifle grooves were deeper toward the breech, becoming shallower as they progressed toward the muzzle. This causes the bullet to be progressively molded into the grooves which increases range and accuracy. Among the first pointed or "conical" bullets were those designed by Captain John Norton of the
British Army The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gur ...
in 1832. Norton's bullet had a hollow base made of
lotus Lotus may refer to: Plants *Lotus (plant), various botanical taxa commonly known as lotus, particularly: ** ''Lotus'' (genus), a genus of terrestrial plants in the family Fabaceae **Lotus flower, a symbolically important aquatic Asian plant also ...
pith that on firing expanded under pressure to engage with a barrel's rifling. The British Board of Ordnance rejected it because spherical bullets had been in use for the previous 300 years. Renowned English gunsmith
William Greener William Greener (1806–1869) was an English inventor and gunmaker. He developed a self-expanding bullet in 1835, an electric lamp in 1846 (patent specification 11076 of that year) some 33 years before Thomas Edison's patent in 1879. William Gree ...
invented the Greener bullet in 1836. Greener fitted the hollow base of an oval bullet with a wooden plug that more reliably forced the base of the bullet to expand and catch the rifling. Tests proved that Greener's bullet was effective, but the military rejected it because, being two parts, they judged it as too complicated to produce. The carabine à tige, developed by Louis-Étienne de Thouvenin in 1844, was an improvement of Delvigne's design. The rifle barrel has a forcing plug in the breech of the barrel to mold the bullet into the rifling with the use of a special ramrod. While successful in increasing accuracy, it was difficult to clean. The soft lead
Minié ball The Minié ball or Minie ball, is a type of hollow-based bullet designed by Claude-Étienne Minié, inventor of the French Minié rifle, for muzzle-loading rifled muskets. It was invented in 1847 and came to prominence in the Crimean War an ...
was first introduced in 1847 by Claude-Étienne Minié, a captain in the French Army. It was another improvement of the work done by Delvigne. The bullet was conical in shape with a hollow cavity in the rear, which was fitted with a small iron cap instead of a wooden plug. When fired, the iron cap forced itself into the hollow cavity at the rear of the bullet, thus expanding the sides of the bullet to grip and engage the rifling. In 1851, the British adopted the Minié ball for their 702-inch Pattern 1851 Minié rifle. In 1855, James Burton, a machinist at the U.S. Armory at Harper's Ferry, West Virginia, improved the Minié ball further by eliminating the metal cup in the bottom of the bullet. The Minié ball first saw widespread use in the
Crimean War The Crimean War, , was fought from October 1853 to February 1856 between Russia and an ultimately victorious alliance of the Ottoman Empire, France, the United Kingdom and Piedmont-Sardinia. Geopolitical causes of the war included t ...
(1853-1856). Roughly 90% of the battlefield casualties in the
American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by state ...
(1861-1865) were caused by Minié balls fired from rifled muskets. A similar bullet called the
Nessler ball The Nessler ball -- or balle Nessler -- is a type of muzzle-loading musket bullet. It was developed to increase the accuracy and range of smoothbore muskets and was used in the Crimean War. It featured a short conical-cylindrical soft lead bull ...
was also developed for
smoothbore A smoothbore weapon is one that has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars. History Early firearms had smoothly bored barrels that fired projectiles without s ...
muskets. Between 1854 and 1857, Sir Joseph Whitworth conducted a long series of rifle experiments and proved, among other points, the advantages of a smaller
bore Bore or Bores often refer to: *Boredom * Drill Relating to holes * Boring (manufacturing), a machining process that enlarges a hole ** Bore (engine), the diameter of a cylinder in a piston engine or a steam locomotive ** Bore (wind instruments), ...
and, in particular, of an elongated bullet. The Whitworth bullet was made to fit the grooves of the rifle mechanically. The Whitworth rifle was never adopted by the government, although it was used extensively for match purposes and target practice between 1857 and 1866. In 1861 W.B. Chace approached President
Abraham Lincoln Abraham Lincoln ( ; February 12, 1809 – April 15, 1865) was an American lawyer, politician, and statesman who served as the 16th president of the United States from 1861 until his assassination in 1865. Lincoln led the nation thro ...
with an improved ball design for muskets. In firing over the
Potomac River The Potomac River () drains the Mid-Atlantic (United States), Mid-Atlantic United States, flowing from the Potomac Highlands of West Virginia, Potomac Highlands into Chesapeake Bay. It is long,U.S. Geological Survey. National Hydrography Datas ...
where the Chace ball and the round ball were alternated, Lincoln observed that the Chace design carried a third or more farther fired at the same elevation. Although Lincoln recommended testing, it never took place. Around 1862, W. E. Metford carried out an exhaustive series of experiments on bullets and rifling, and he invented the important system of light rifling with increasing spiral and a hardened bullet. The combined result was that, in December 1888, the Lee–Metford small-bore (
.303 .303 may refer to: * .303 British, a rifle cartridge * .303 Savage, a rifle cartridge * Lee–Enfield The Lee–Enfield or Enfield is a bolt-action, magazine-fed repeating rifle that served as the main firearm of the military forces of the B ...
", 7.70 mm) rifle, Mark I, was adopted for the British army. The Lee–Metford was the predecessor of the Lee–Enfield.


Modern bullets

The next important change in the history of the rifle bullet occurred in 1882, when Lieutenant Colonel Eduard Rubin, director of the Swiss Army Laboratory at Thun, invented the copper-jacketed bullet — an elongated bullet with a lead core in a copper jacket. It was also small bore (7.5mm and 8mm) and it is the precursor of the 8mm ''Lebel bullet'' adopted for the
smokeless powder Finnish smokeless powderSmokeless powder is a type of propellant used in firearms and artillery that produces less smoke and less fouling when fired compared to gunpowder ("black powder"). The combustion products are mainly gaseous, compared to ...
ammunition of the Lebel Model 1886 rifle. The surface of lead bullets fired at high velocity may melt from the hot gases behind and friction within the bore. Because copper has a higher
melting point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends ...
, and greater
specific heat capacity In thermodynamics, the specific heat capacity (symbol ) of a substance is the heat capacity of a sample of the substance divided by the mass of the sample, also sometimes referred to as massic heat capacity. Informally, it is the amount of heat t ...
, and higher
hardness In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion (mechanical), abrasion. In general, different materials differ in their hardn ...
, copper-jacketed bullets allow greater muzzle velocities. European advances in aerodynamics led to the pointed
spitzer bullet The spitzer bullet (or spire point) is a pointed projectile that is primarily used in small-arms. The pointed nose shape, which was developed for military purposes in the late 19th and early 20th century, was a major design improvement compared ...
. By the beginning of the 20th century, most world armies had begun the transition to spitzer bullets. These bullets flew for greater distances more accurately and transferred more
kinetic energy In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its a ...
. Spitzer bullets combined with
machine gun A machine gun is a fully automatic, rifled autoloading firearm designed for sustained direct fire with rifle cartridges. Other automatic firearms such as automatic shotguns and automatic rifles (including assault rifles and battle rifl ...
s greatly increased lethality on the battlefield. Spitzer bullets were streamlined at the base with the boat tail. In the trajectory of a bullet, as air passes over a bullet at high speed, a vacuum is created at the end of the bullet, slowing the projectile. The streamlined boat tail design reduces this form drag by allowing the air to flow along the surface of the tapering end. The resulting aerodynamic advantage is currently seen as the optimum shape for rifle technology. The first combination spitzer and boat-tail bullet, named ''balle'' D by its inventor Captain Georges Desaleux, was introduced as standard military ammunition in 1901, for the French Lebel Model 1886 rifle. A ballistic tip bullet is a hollow-point rifle bullet that has a plastic tip on the end of the bullet. This improves
external ballistics External ballistics or exterior ballistics is the part of ballistics that deals with the behavior of a projectile in flight. The projectile may be powered or un-powered, guided or unguided, spin or fin stabilized, flying through an atmosphere or ...
by streamlining the bullet, allowing it to cut through the air more easily, and improves terminal ballistics by allowing the bullet to act as a jacketed hollow point. As a side effect, it also feeds better in weapons that have trouble feeding rounds that are not full metal jacket rounds.


Design

Bullet designs have to solve two primary problems. In the barrel, they must first form a seal with the gun's bore. If a strong seal is not achieved, gas from the propellant charge leaks past the bullet, thus reducing efficiency and possibly accuracy. The bullet must also engage the rifling without damaging or excessively fouling the gun's bore and without distorting the bullet, which will also reduce accuracy. Bullets must have a surface that forms this seal without excessive friction. These interactions between bullet and bore are termed internal ballistics. Bullets must be produced to a high standard, as surface imperfections can affect firing accuracy. The physics affecting the bullet once it leaves the barrel is termed
external ballistics External ballistics or exterior ballistics is the part of ballistics that deals with the behavior of a projectile in flight. The projectile may be powered or un-powered, guided or unguided, spin or fin stabilized, flying through an atmosphere or ...
. The primary factors affecting the aerodynamics of a bullet in flight are the bullet's shape and the rotation imparted by the rifling of the gun barrel. Rotational forces stabilize the bullet gyroscopically as well as aerodynamically. Any asymmetry in the bullet is largely canceled as it spins. However, a spin rate greater than the optimum value adds more trouble than good, by magnifying the smaller asymmetries or sometimes resulting in the bullet breaking apart in flight. With smooth-bore firearms, a spherical shape is optimal because no matter how the bullet is oriented, its aerodynamics are similar. These unstable bullets tumble erratically and provide only moderate accuracy; however, the aerodynamic shape changed little for centuries. Generally, bullet shapes are a compromise between aerodynamics, interior ballistic necessities, and terminal ballistics requirements. Terminal ballistics and stopping power are aspects of bullet design that affect what happens when a bullet impacts with an object. The outcome of the impact is determined by the composition and density of the target material, the
angle of incidence Angle of incidence is a measure of deviation of something from "straight on" and may refer to: * Angle of incidence (aerodynamics), angle between a wing chord and the longitudinal axis, as distinct from angle of attack In fluid dynamics, ang ...
, and the velocity and physical characteristics of the bullet. Bullets are generally designed to penetrate, deform, or break apart. For a given material and bullet, the strike velocity is the primary factor that determines which outcome is achieved. Bullet shapes are many and varied. With a mold, bullets can be made at home for reloading ammunition, where local laws allow. Hand-casting, however, is only time- and cost-effective for solid lead bullets. Cast and jacketed bullets are also commercially available from numerous manufacturers for handloading and are most often more convenient than casting bullets from bulk or scrap lead.


Propulsion

Propulsion of the ball can happen via several methods: * by using only gunpowder (as in
flintlock Flintlock is a general term for any firearm that uses a flint-striking ignition mechanism, the first of which appeared in Western Europe in the early 16th century. The term may also apply to a particular form of the mechanism itself, also known ...
weapons) * by using a
percussion cap The percussion cap or percussion primer, introduced in the early 1820s, is a type of single-use percussion ignition device for muzzle loader firearm locks enabling them to fire reliably in any weather condition. This crucial invention gave rise ...
and gunpowder (as in percussion weapons) * by using a cartridge


Materials

Bullets for black powder, or muzzle-loading firearms, were classically molded from pure
lead Lead is a chemical element with the Symbol (chemistry), symbol Pb (from the Latin ) and atomic number 82. It is a heavy metals, heavy metal that is density, denser than most common materials. Lead is Mohs scale of mineral hardness#Intermediate ...
. This worked well for low-speed bullets, fired at velocities of less than 450 m/s (1,475 ft/s). For slightly higher-speed bullets fired in modern firearms, a harder
alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductilit ...
of lead and tin or typesetter's lead (used to mold linotype) works very well. For even higher-speed bullet use, jacketed lead bullets are used. The common element in all of these, lead, is widely used because it is very dense, thereby providing a high amount of mass—and thus, kinetic energy—for a given volume. Lead is also cheap, easy to obtain, easy to work, and melts at a low temperature, which results in comparatively easy fabrication of bullets. * Lead: simple
cast Cast may refer to: Music * Cast (band), an English alternative rock band * Cast (Mexican band), a progressive Mexican rock band * The Cast, a Scottish musical duo: Mairi Campbell and Dave Francis * ''Cast'', a 2012 album by Trespassers William ...
, extruded,
swaged Swaging () is a forging process in which the dimensions of an item are altered using dies into which the item is forced. Swaging is usually a cold working process, but also may be hot worked. The term swage may apply to the process (verb) or ...
, or otherwise fabricated lead slugs are the simplest form of bullets. At speeds of greater than 300 m/s (1,000 ft/s) (common in most handguns), lead is deposited in rifled bores at an ever-increasing rate. Alloying the lead with a small percentage of tin and/or
antimony Antimony is a chemical element with the symbol Sb (from la, stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient ti ...
serves to reduce this effect but grows less effective as velocities are increased. A cup made of harder metal, such as copper, placed at the base of the bullet and called a gas check, is often used to decrease lead deposits by protecting the rear of the bullet against melting when fired at higher pressures, but this does not solve the problem at higher velocities. A modern solution is to powder coat the lead projectile, encasing it in a protective skin, allowing higher velocities to be achieved without lead deposits. * Jacketed lead: bullets intended for even higher-velocity applications generally have a lead core that is jacketed or plated with
gilding metal Gilding metal is a form of brass (an alloy of copper and zinc) with a much higher copper content than zinc content. Exact figures range from 95% copper and 5% zinc to “8 parts copper to 1 of zinc” (11% zinc) in British Army Dress Regulations. ...
, cupronickel,
copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish ...
alloys, or steel; a thin layer of harder metal protects the softer lead core when the bullet is passing through the barrel and during flight, which allows delivering the bullet intact to the target. There, the heavy lead core delivers its kinetic energy to the target. Full metal jacket or "ball" bullets (cartridges with ball bullets, which despite the name are not spherical, are called ball ammunition) are completely encased in the harder metal jacket, except for the base. Some bullet jackets do not extend to the front of the bullet, to aid expansion and increase lethality; these are called soft point (if the exposed lead tip is solid) or hollow point bullets (if a cavity or hole is present). Steel bullets are often plated with copper or other metals for corrosion resistance during long periods of storage. Synthetic jacket materials such as
nylon Nylon is a generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic. Nylon is a silk-like thermoplastic, generally made from pet ...
and Teflon have been used, with limited success, especially in rifles; however, hollow point bullets with plastic aerodynamic tips have been very successful at both improving accuracy and enhancing expansion. Newer plastic coatings for handgun bullets, such as Teflon-coated bullets, are making their way into the market. * Solid or '' monolithic solid'': mono-metal bullets intended for deep penetration in big game animals and slender shaped very-low-drag projectiles for long range shooting are produced out of metals like oxygen-free copper and alloys like cupronickel, tellurium copper and
brass Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other wit ...
(e.g., highly machinable UNS C36000 free-cutting brass). Often these projectiles are turned on precision CNC lathes. In the case of solids, and the ruggedness of the game animals on which they are used, e.g., the African buffalo or elephant, expansion is almost entirely relinquished for the necessary penetration. In shotgunning, "slug" loads are often solid large single lead projectiles, sometimes with a hollow point, used for deer or wild pig hunting in jurisdictions that do not allow hunting with rifles (because a missed slug shot will travel considerably less far than a rifle bullet). **Fluted: in appearance, these are solid bullets with scalloped sides (missing material). The theory is that the flutes produce hydraulic jetting when passing through tissue, creating a wound channel larger than that made by conventional
expanding ammunition Expanding bullets, also known colloquially as dumdum bullets, are projectiles designed to expand on impact. This causes the bullet to increase in diameter, to combat over-penetration and produce a larger wound, thus dealing more damage to a liv ...
such as hollow point bullets. **Hard cast: a hard lead alloy intended to reduce fouling of rifling grooves (especially of the polygonal rifling used in some popular pistols). Benefits include simpler manufacture than jacketed bullets and good performance against hard targets; limitations are an inability to
mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is ...
and subsequent over-penetration of soft targets. * Blank: wax, paper, plastic, and other materials are used to simulate live gunfire and are intended only to hold the powder in a blank cartridge and to produce noise, flame and smoke. The "bullet" may be captured in a purpose-designed device or it may be allowed to expend what little energy it has in the air. Some blank cartridges are crimped or closed at the end and do not contain any bullet; some are fully loaded cartridges (without bullets) designed to propel rifle grenades. The force of the expanding gas from blank cartridges can be lethal at short range; numerous tragic accidents have occurred with blank cartridges (e.g., the death of actor Jon-Erik Hexum). * Practice: made from lightweight materials like rubber, wax, wood, plastic, or lightweight metal, practice bullets are intended for short-range target work only. Because of their weight and low velocity, they have limited range. * Polymer: these are metal-polymer composites, generally lighter and having higher velocities than pure metal bullets of the same dimensions. They permit unusual designs that are difficult with conventional casting or lathing. * Less lethal, or ''less than lethal'': Rubber bullets, plastic bullets, and beanbags are designed to be non-lethal, e.g., for use in
riot control Riot control measures are used by law enforcement, military, paramilitary or security forces to control, disperse, and arrest people who are involved in a riot, unlawful demonstration or unlawful protest. If a riot is spontaneous and irra ...
. They are generally low velocity and are fired from shotguns, grenade launchers, paint ball guns, or specially designed firearms and air gun devices. * Incendiary: these bullets are made with explosive or flammable mixtures in the tips that are designed to ignite on contact with a target. The intent is to ignite fuel or munitions in the target area, thereby adding to the destructive power of the bullet. *
Exploding An explosion is a rapid expansion in volume associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Supersonic explosions created by high explosives are known ...
: similar to the incendiary bullet, this type of projectile is designed to explode upon hitting a hard surface, preferably the bone of the intended target. Not to be mistaken for cannon shells or grenades with fuse devices, these bullets have only cavities filled with a small amount of high explosive depending on the velocity and deformation upon impact to detonate. Exploding bullets have been used in various heavy machine guns and in anti-materiel rifles. *
Tracer Tracer may refer to: Science * Flow tracer, any fluid property used to track fluid motion * Fluorescent tracer, a substance such as 2-NBDG containing a fluorophore that is used for tracking purposes * Histochemical tracer, a substance used for tr ...
: these have hollow backs, filled with a
flare A flare, also sometimes called a fusée, fusee, or bengala in some Latin-speaking countries, is a type of pyrotechnic that produces a bright light or intense heat without an explosion. Flares are used for distress signaling, illumination, o ...
material. Usually this is a mixture of
magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...
, a
perchlorate A perchlorate is a chemical compound containing the perchlorate ion, . The majority of perchlorates are commercially produced salts. They are mainly used as oxidizers for pyrotechnic devices and to control static electricity in food packaging. ...
, and
strontium Strontium is the chemical element with the symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is ...
salts to yield a bright red color, although other materials providing other colors have also sometimes been used. Tracer material burns out after a certain amount of time. This allows the shooter to visually trace the flight path of the projectile and thus make necessary ballistic corrections, without having to confirm projectile impacts and without even using the
sights A sight is an aiming device used to assist in visually aligning ranged weapons, surveying instruments or optical illumination equipments with the intended target. Sights can be a simple set or system of physical markers that have to be aligne ...
of the weapon. This type of round is also used by all branches of the
United States military The United States Armed Forces are the military forces of the United States. The armed forces consists of six service branches: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. The president of the United States is ...
in combat environments as a signaling device to friendly forces. Normally it is loaded at a four to one ratio with ball ammunition. * Armor-piercing: jacketed designs where the core material is a very hard, high-density metal such as
tungsten Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isol ...
,
tungsten carbide Tungsten carbide (chemical formula: WC) is a chemical compound (specifically, a carbide) containing equal parts of tungsten and carbon atoms. In its most basic form, tungsten carbide is a fine gray powder, but it can be pressed and formed int ...
,
depleted uranium Depleted uranium (DU; also referred to in the past as Q-metal, depletalloy or D-38) is uranium with a lower content of the fissile isotope than natural uranium.: "Depleted uranium possesses only 60% of the radioactivity of natural uranium, ...
, or steel. A pointed tip is often used, but a flat tip on the penetrator portion is generally more effective. * Nontoxic shot: steel,
bismuth Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs ...
, tungsten, and other alloys prevent release of toxic lead into the environment. Regulations in several countries mandate the use of nontoxic projectiles especially when waterfowl hunting. It has been found that birds swallow small lead shot for their
gizzards The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ found in the digestive tract of some animals, including archosaurs (pterosaurs, crocodiles, alligators, dinosaurs, birds), earthworms, some gastropods, som ...
to grind food (as they would swallow pebbles of similar size), and the effects of
lead poisoning Lead poisoning, also known as plumbism and saturnism, is a type of metal poisoning caused by lead in the body. The brain is the most sensitive. Symptoms may include abdominal pain, constipation, headaches, irritability, memory problems, inferti ...
by grinding of lead pellets against food means lead poisoning effects are magnified. Such concerns apply primarily to shotguns firing pellets ( shot) and not bullets, but there is evidence suggesting that consumption of spent rifle and pistol ammunition is also hazardous to wildlife. Reduction of hazardous substances legislation has also been applied to bullets on occasion to reduce the impact of lead on the environment at
shooting range A shooting range, firing range, gun range or shooting ground is a specialized facility, venue or field designed specifically for firearm usage qualifications, training, practice or competitions. Some shooting ranges are operated by militar ...
s. * Blended-metal: bullets made using cores from powdered metals other than lead with binder or sometimes sintered. * Frangible: designed to disintegrate into tiny particles upon impact to minimize their penetration for reasons of range safety, to limit environmental impact, or to limit the shoot-through danger behind the intended target. An example is the Glaser Safety Slug, usually a pistol caliber bullet made from an amalgam of lead shot and a hard (and thus frangible) plastic binder designed to penetrate a human target and release its component shot pellets without exiting the target. * Multiple projectile: bullets that are made of separate slugs that fit together inside the cartridge and act as a single projectile inside the barrel as they are fired. The projectiles part in flight but are held in formation by tethers that keep the individual parts of the "bullet" from flying too far away from each other. The intention of such ammo is to increase hit chance by giving a shot-like spread to rifled slug firing guns, while maintaining a consistency in shot groupings. Multiple impact bullets may be less stable in flight than conventional solid bullets because of the added
drag Drag or The Drag may refer to: Places * Drag, Norway, a village in Tysfjord municipality, Nordland, Norway * ''Drág'', the Hungarian name for Dragu Commune in Sălaj County, Romania * Drag (Austin, Texas), the portion of Guadalupe Street adj ...
from the tether line holding the pieces in formation, and each projectile affects the flight of all the others. This may limit the benefit provided by the spread of each bullet at longer ranges.


Treaties and prohibitions

Poisonous bullets were a subject to an international agreement as early as the
Strasbourg Agreement (1675) The Strasbourg Agreement of 27 August 1675 is the first international agreement banning the use of chemical weapons. The treaty was signed between France and the Holy Roman Empire, and was created in response to the use of poisoned bullets. The us ...
. The Saint Petersburg Declaration of 1868 prohibited the use of explosive projectiles weighing less than 400 grams; it was reasoned that more deadly bullets would lead to less suffering. The Hague Convention prohibits certain kinds of ammunition for use by uniformed military personnel against the uniformed military personnel of opposing forces. These include projectiles that explode within an individual, poisoned and expanding bullets. Protocol III of the 1983 Convention on Certain Conventional Weapons, an annexed protocol to the
Geneva Conventions upright=1.15, Original document in single pages, 1864 The Geneva Conventions are four treaties, and three additional protocols, that establish international legal standards for humanitarian treatment in war. The singular term ''Geneva Conv ...
, prohibits the use of incendiary ammunitions against civilians. In December 2014, a federal appeals court denied a lawsuit by environmental groups that the EPA must use the Toxic Substances Control Act to regulate lead in shells and cartridges. The groups sought to regulate "spent lead", yet EPA could not regulate spent lead without also regulating cartridges and shells, per the court. The
United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it ...
announced that the agency does not have the legal authority to regulate this type of product (lead bullets) under the Toxic Substances Control Act nor is the agency seeking such authority. With some nontoxic shot, e.g., steel shot, care must be taken to shoot only in shotguns (and with chokes) specifically designed and designated for steel shot; for other, particularly older, shotguns, serious damage to the barrel and chokes can occur. And because steel is lighter and less dense than lead, larger sized pellets must be used, thus reducing the number of pellets in a given charge of shot and possibly limiting patterns on the target; other formulations do not present typically this disability.


Abbreviations

:2F – Two-part controlled fragmenting :ACC – Remington Accelerator (see sabot) :ACP – Automatic Colt Pistol :AE – Action express :AGS – African Grand Slam (Speer) :AP – Armor piercing (has a depleted uranium or other hard metal core) :APT – Armor-piercing tracer :API – Armor-piercing incendiary :API-T – Armor-piercing incendiary tracer :APFSDS – Armor-piercing fin stabilized discarding sabot round :B – Ball :B2F – Brass two-part fragmenting :BBWC – Bevel base wadcutter :BEB – Brass enclosed base :BJHP – Brass jacketed hollow point :Blitz –
Sierra Sierra (Spanish for "mountain range" and "saw", from Latin '' serra'') may refer to the following: Places Mountains and mountain ranges * Sierra de Juárez, a mountain range in Baja California, Mexico * Sierra de las Nieves, a mountain range i ...
BlitzKing :BMG – Browning Machine Gun :BrPT – Bronze point :Bt – Boat-tail :BtHP – Boat-tail hollow point :C2F – Civilian two-part fragmenting :CB – Cast bullet :CL, C-L – Remington Core-Lokt :CMJ – Complete metal jacket, electroplated, not truly jacketed :CN – Cupronicknel :CNCS – Cupronickel-clad steel :CTFB – Closed tip flat Bbse :DBBWC – Double bevel based wadcutter :DEWC – Double ended wadcutter :DGS – Dangerous game solid (Hornady) :DGX – Dangerous game expanding (Hornady) :DU –
Depleted uranium Depleted uranium (DU; also referred to in the past as Q-metal, depletalloy or D-38) is uranium with a lower content of the fissile isotope than natural uranium.: "Depleted uranium possesses only 60% of the radioactivity of natural uranium, ...
:EFMJ – Expanding full metal jacket :EVO, FTX – Hornady Leverevolution flex tip expanding :EVO – RWS Evolution bullet :FMC – Full metal case :FMJ – Full metal jacket :FMJBT – Full metal jacket boat-tail :FN – Dangerous game solid flat nose :FNEB – Flat nose enclosed base :FP – Flat point :FP – Full patch :FST – Winchester Fail Safe Talon :GAP (G.A.P.) – Glock Automatic Pistol :GC – Gas check :GD – Speer Gold Dot :GDHP – Speer Gold Dot hollow point :GM – Gilding metal :GMCS – Gilding metal-clad steel :GS – Remington Golden Saber :GSC – GS Custom turned copper bullet :HAP – Hornady Action Pistol :HBWC – Hollow base wadcutter :HC – Hard cast :HE-IT – High explosive incendiary tracer :HFN – Hard cast flat nose :HP – Hollow point :HPBT – Hollow point boat tail :HPCB – Heavy plate concave base :HPJ – High performance jacketed :HS – Federal Hydra-Shok :HST – Federal Hi-Shok Two :HV – Low friction drive band high velocity :ID-Classic – RWS fragmentation bullet, ex-''TIG'' after Brenneke-license was not renewed :I-T – Incendiary tracer :IB – Interbond (Hornady) :J – Jacketed :JAP – Jacketed aluminium point :JFP – Jacketed flat point :JHC – Jacketed hollow cavity : JHP – Jacketed hollow point :JHP/sabot – Jacketed hollow point/ sabot :JSP – Jacketed soft point :L – Lead :L-C – Lead combat :L-T – Lead target :LF – Lead free :LFN – Long flat nose :LFP – Lead flat point :LHP – Lead hollow point :LR – Long Rifle :LRN – Lead round nose :LSWC – Lead semiwadcutter :LSWC-GC – Lead semiwadcutter gas checked :LWC – Lead wadcutter :LTC – Lead truncated cone :MC – Metal cased :MHP – Match hollow point :MK –
Sierra Sierra (Spanish for "mountain range" and "saw", from Latin '' serra'') may refer to the following: Places Mountains and mountain ranges * Sierra de Juárez, a mountain range in Baja California, Mexico * Sierra de las Nieves, a mountain range i ...
MatchKing :MRWC – Mid-range wadcutter :MP – Metal point :NP – Nosler partition :OTM – Open tip match :OWC – Ogival wadcutter :P – Practice, proof :PB – Lead bullet :PB – Parabellum :PL – Remington Power-Lokt :PnPT – Pneumatic point :PPL – Paper patched lead :PSP – Plated soft point :PSP, PTDSP – Pointed soft point :PRN – Plated round nose :RBT – Rebated boat tail :RN – Round nose :RNFP – Round nose flat point :RNL – Round nose lead :SCHP – Solid copper hollow point :SJ – Semi-jacketed :SJHP – Semi-jacketed hollow point :SJSP – Semi-jacketed soft point :SLAP – Saboted light armor penetrator :SP – Soft point :SP – Spire point :Sp, SPTZ – Spitzer :SPC – Special purpose cartridge :SpHP – Spitzer hollow point :SST – Hornady Super shock tip :SSp – Semi-spitzer :ST – Silver tip :STHP – Silver tip hollow point :SWC – Semiwadcutter :SX – Super explosive :SXT – Winchester Ranger supreme expansion technology :T – Tracer :TAG – Brenneke lead-free bullet (german: Torpedo Alternativ-Geschoß) :TBBC – Carter/Speer Trophy Bonded Bear Claw soft point :TBSS – Carter/Speer Trophy Bonded Sledgehammer solid :TC – Truncated cone :THV – Terminal high velocity :TIG – Brenneke fragmentation bullet (german: Torpedo Ideal-Geschoß) :TMJ – Total metal jacket :TNT – Speer TNT :TUG – Brenneke deformation bullet (german: Torpedo Universal-Geschoß) :TOG – Brenneke deformation bullet (german: Torpedo Optimal-Geschoß) :UmbPT – Umbrella point :UNI-Classic – RWS deformation bullet, ex-''TUG'' after Brenneke-license was not renewed. :VMAX – Hornady V-Max :WMR – Winchester Magnum Rimfire :VLD –
Very low drag A very-low-drag bullet (VLD) is primarily a small arms ballistics development of the 1980s–1990s, driven by the design objective of bullets with higher degrees of accuracy and kinetic efficiency, especially at extended ranges. To achieve this, ...
:WC – Wadcutter :WFN – Wide flat nose :WFNGC – Wide flat nose gas check :WLN – Wide long nose :X – Barnes X-bullet :XTP – Hornady Extreme Terminal Performance


See also

*
Flechette A flechette ( ) is a pointed steel projectile with a vaned tail for stable flight. The name comes from French , "little arrow" or "dart", and sometimes retains the acute accent in English: fléchette. They have been used as ballistic weapons sinc ...
* List of handgun cartridges *
List of rifle cartridges List of rifle cartridges, by primer type, calibre and name. File:Cartridge Sample 2.jpg, 350px, From left to right: 1 .17 HM2,2 .17 HMR, 2.5 .17 wsm, 3 .22LR, 4 .22 WMR, 5 .17/23 SMc, 6 5mm/35 SMc, 7 .22 Hornet, 8 .223 Remington, 9 .223 WSS ...
* Meplat * Smart bullet * Table of handgun and rifle cartridges * The Second Amendment to the US Constitution


References


External links


High speed imaging of in flight bullet transition ballistics
* ttps://archive.today/20130101212928/http://arizonagunlist.com/ammunition_types.html Arizona Gun List – ammunition typesbr>Bullets for BeginnersRemington Core-Lokt, Bronze Point & Power-Lokt Centerfire Ammunition

How To Make GUN BULLET , How To Machines
{{Authority control Projectiles * Articles containing video clips