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A bullet is a kinetic projectile, a component of firearm ammunition that is shot from a gun barrel. The term is from Middle French, originating as the diminutive of the word boulle (boullet), which means "small ball".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, target shooting, training and combat. bullets are often tapered, making them more aerodynamic. Bullet sizes are expressed by their weights and diameters (referred to as "calibers") in both imperial and metric measurement systems. For example: 55 grain .223 caliber bullets are of the same weight and caliber as 3.56 gram 5.56mm caliber bullets. Bullets do not normally contain explosives (see Incendiary ammunition and Exploding bullet), but strike or damage the intended target by transferring kinetic energy upon impact and penetration (see terminal ballistics).
Bullets are available singly (as in muzzle-loading and cap and ball firearms),but are more often packaged with propellant as cartridges ("rounds" of ammunition). Bullets are components of paper cartridges, or (much more commonly) in the form of metallic cartridges. 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. A cartridge is a combination package of the bullet (i.e., the projectile), the case (which holds everything together), the propellant (which provides the majority of the energy to launch the projectile) and the primer (which ignites the propellant). This use of the term bullet (when intending to describe a cartridge) often leads to confusion when a cartridge, and all its components, are specifically referred to. The cartridges, in turn, may be held in a magazine or a belt (for rapid-fire weapons).
The bullets used in many cartridges are fired at muzzle velocities faster than the speed of sound 343 metres per second (1,130 ft/s) in dry air at 20 °C (68 °F)—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-like crack as the supersonic bullet pierces through the air creating a sonic boom. Bullet speeds at various stages of flight depend on intrinsic factors such as sectional density, aerodynamic profile and ballistic coefficient, and extrinsic factors such as barometric pressure, 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, can be substantially quieter than a supersonic cartridge, such as the .223 Remington, even without the use of a suppressor.—about
Bullets shot by firearms can be used for target practice or to injure or kill animals, or people. Death can be by blood loss or damage to vital organs, or even asphyxiation 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), rubber bullets, tasers, bean bag rounds, grenade launchers, flash bangs, tear gas, RPGs, and missile launchers.
While the first recorded use of gunpowder in Europe was in 1247, it was invented in China during the 9th century. The cannon appeared in 1327, and the 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 (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 and matchlock arquebus brought about the use of cast lead balls as projectiles. The original round musket 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 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.
The first half of the nineteenth century saw a distinct change in the shape and function of the bullet. In 1826, Henri-Gustave Delvigne, a French infantry officer, invented a breech with abrupt shoulders on which a spherical bullet was rammed down until it caught the rifling grooves. Delvigne's method, however, deformed the bullet and was inaccurate.
Square bullets have origins that almost pre-date civilization and were used by slingers in slings. They were typically made out of copper or lead. The most notable use of square bullet designs was done 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 era was soon discontinued due to irregular and unpredictable flight patterns.
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", these 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.
The Thouvenin 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 extremely hard to clean. These improvements were the basis for the development of the Minié ball.
Among the first pointed or "conical" bullets were those designed by Captain John Norton of the British Army in 1832. Norton's bullet had a hollow base made of lotus 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 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 extremely effective, but the military rejected it because, being two parts, they judged it as too complicated to produce.
The soft lead Minié ball 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. As designed by Minié, 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 US 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 (1853-1856). Roughly 90% of the battlefield casualties in the American Civil War (1861-1865) were caused by Minié balls fired from rifled muskets.
A similar bullet called the Nessler ball was also developed for smoothbore 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 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, when it was gradually superseded by Metford's.
In 1861 W.B. Chace approached President Abraham Lincoln with an improved ball design for muskets. In firing over the Potomac river 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.
About 1862 and later, W. E. Metford carried out an exhaustive series of experiments on bullets and rifling, and 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", 7.70 mm) rifle, Mark I, was finally adopted for the British army. The Lee–Metford was the predecessor of the Lee–Enfield.
The next important change in the history of the rifle bullet occurred in 1882, when Lt. 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 ammunition of the Lebel Model 1886 rifle.
The surface of lead bullets fired at high velocity may melt due to hot gases behind and friction with the bore. Because copper has a higher melting point, and greater specific heat capacity and hardness, copper-jacketed bullets allow greater muzzle velocities.
European advances in aerodynamics led to the pointed spitzer bullet. By the beginning of the twentieth century, most world armies had begun to transition to spitzer bullets. These bullets flew for greater distances more accurately and carried more energy with them. Spitzer bullets combined with machine guns greatly increased the lethality of the battlefield.
The latest advancement in bullet shape was the boat tail, a streamlined base for spitzer bullets. The vacuum created as air moving at high speed passes over the end of a bullet slows 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" from its inventor (a lieutenant-colonel 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 itself. This improves external ballistics 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 JHP on impact.
As a side effect, it also feeds better in weapons that have trouble feeding rounds that are not FMJ rounds.
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. 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 exploding midway in flight. With smooth-bore firearms, a spherical shape was optimum because no matter how it was oriented, it presented a uniform front. These unstable bullets tumbled erratically and provided 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. Another method of stabilization is to place the center of mass of the bullet as far forward as is practical, which is how the Minié ball and the shuttlecock are designed. This makes the bullet fly front-forward by means of aerodynamics.
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, and the velocity and physical characteristics of the bullet itself. 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, and an array of them can be found in any reloading manual that sells bullet molds. Mold manufacturers such as RCBS,Paul Jones Moulds, and David Mos offer many different calibers and designs. 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 hand loading and are most often more convenient than casting bullets from bulk or scrap lead.
Propulsion of the ball can happen via several methods:
Bullets for black powder, or muzzle-loading firearms, were classically molded from pure lead. 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 of lead and tin or typesetter's lead (used to mold linotype) works very well. For even higher-speed bullet use, jacketed coated 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.
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Poisonous bullets were a subject to an international agreement as early as the Strasbourg Agreement (1675).
The St. 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 annexe to the Geneva Conventions, prohibits the use of incendiary ammunitions against civilians.
Some jurisdictions acting on environmental concerns have banned hunting with lead bullets and shotgun pellets.
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.
A rifle is a long-barrelled firearm designed for accurate shooting, with a barrel that has a helical pattern of grooves (rifling) cut into the bore wall. In keeping with their focus on accuracy, rifles are typically designed to be held with both hands and braced firmly against the shooter's shoulder via a buttstock for stability during shooting. Rifles are used extensively in warfare, self defense, law enforcement, hunting, and shooting sports.
A hollow-point bullet is a type of expanding bullet used for controlled penetration, where over-penetration could cause collateral damage. In target shooting, they are used for greater accuracy due to the larger meplat. Hollow point bullets are more accurate and predictable compared to pointed bullets which, despite having a higher ballistic coefficient (BC), are more sensitive to bullet harmonic characteristics and wind deflection.
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 the projectile longitudinally by conservation of angular momentum, improving its aerodynamic stability and accuracy over smoothbore designs.
Terminal ballistics, a sub-field of ballistics, is the study of the behavior and effects of a projectile when it hits and transfers its energy to a target. Bullet design and the velocity of impact largely determine the effectiveness of its impact.
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. This leads to a living target being incapacitated faster. For this reason they are used for hunting and by most police departments, but are generally prohibited for use in war. Two typical designs are the hollow-point bullet and the soft-point bullet.
A soft-point bullet (SP), also known as a soft-nosed bullet, is a jacketed expanding bullet with a soft metal core enclosed by a stronger metal jacket left open at the forward tip. A soft-point bullet is intended to expand upon striking flesh to cause a wound diameter greater than the bullet diameter. Jacketed soft point bullets are usually abbreviated JSP in the ammunition and reloading industry.
A wadcutter is a special-purpose flat-fronted bullet specifically designed for shooting paper targets, usually at close range and at subsonic velocities typically under approximately 900 ft/s (274 m/s). Wadcutters have also found favor for use in self-defense guns, such as .38 caliber snubnosed revolvers, where, due to short barrel lengths, maximum bullet velocities are usually low, typically under 900 ft/s (274 m/s), and improved lethality is desired. Wadcutters are often used in handgun and airgun competitions.
A gun barrel is a crucial part of gun-type ranged weapons such as small firearms, artillery pieces and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure gas(es) is used to propel a projectile out of the front end (muzzle) at a high velocity. The hollow interior of the barrel is called the bore, and the diameter of the bore is called its caliber, usually measured in inches or millimetres.
The .22 Long Rifle or simply .22 LR is a long-established variety of .22 caliber rimfire ammunition originating from the United States. It is used in a wide range of rifles, pistols, revolvers, smoothbore shotguns, and submachine guns.
Internal ballistics, a subfield of ballistics, is the study of the propulsion of a projectile.
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 muzzleloaded rifled muskets. It came to prominence in the Crimean War and the American Civil War. Both the American Springfield Model 1861 and the British Pattern 1853 Enfield rifled muskets, the most common weapons used during the American Civil War, used the Minié ball.
The .30-06 Springfield cartridge, 7.62×63mm in metric notation and called ".30 Gov't '06" by Winchester, was introduced to the United States Army in 1906 and later standardized; it remained in use until the late-1970s. The ".30" refers to the caliber of the bullet in inches. The "06" refers to the year the cartridge was adopted, 1906. It replaced the .30-03, 6mm Lee Navy, and .30-40 Krag cartridges. The .30-06 remained the U.S. Army's primary rifle and machine gun cartridge for nearly 50 years before being replaced by the 7.62×51mm NATO and 5.56×45mm NATO, both of which remain in current U.S. and NATO service. It remains a very popular sporting round, with ammunition produced by all major manufacturers.
The .303 British or 7.7×56mmR, is a .303-inch (7.7 mm) calibre rimmed rifle cartridge.
A modern shotgun slug is a heavy projectile made of lead, copper, or other material and fired from a shotgun. Slugs are designed for hunting large game, self-defense, and other uses. The first effective modern shotgun slug was introduced by Wilhelm Brenneke in 1898, and his design remains in use today. Most shotgun slugs are designed to be fired through a cylinder bore or an improved cylinder choke, rifled choke tubes, or fully rifled bores. Slugs differ from round-ball lead projectiles in that they are stabilized in some manner.
In the field of firearms and airguns, obturation denotes necessary barrel blockage or fit by a deformed soft projectile. A bullet or pellet, made of soft material and often with a concave base, will flare under the heat and pressure of firing, filling the bore and engaging the barrel's rifling. The mechanism by which an undersized soft-metal projectile enlarges to fill the barrel is, for hollow-base bullets, expansion from gas pressure within the base cavity and, for solid-base bullets, "upsetting"—the combined shortening and thickening that occurs when a malleable metal object is struck forcibly at one end.
Armor-piercing bullets for rifle and handgun cartridges are designed to penetrate ballistic armor and protective shields intended to stop or deflect conventional bullets. Although bullet design is an important factor with regard to armor penetration, the ability of any given projectile to penetrate ballistic armor increases with increasing velocity. Rifle cartridges typically discharge bullets at higher muzzle velocity than handgun cartridges due to larger propellant charge. However, even the same cartridge fired from a rifle will, in almost all common cases, have a higher velocity than when fired from a handgun. This is due to the longer period of acceleration available within the longer gun barrel of rifles, which allow adequate time for the propellant to fully ignite before the projectile exits the barrel. For this reason, bullets fired from rifles may be more capable of piercing armor than similar or identical bullets fired from handguns. In addition, a small-caliber bullet has higher sectional density than a larger-caliber bullet of the same weight, and thus more capable of defeating body armor.
The 5.45×39mm cartridge is a rimless bottlenecked intermediate cartridge. It was introduced into service in 1974 by the Soviet Union for use with the new AK-74. The 5.45×39mm gradually supplemented, then largely replaced the 7.62×39mm cartridge in Soviet and Warsaw Pact service as the primary military service rifle cartridge.
Federal Premium Ammunition is an American ammunition manufacturer. It is a wholly owned subsidiary of Vista Outdoor and is located in Anoka, Minnesota. With a work force of nearly 1,500, Federal makes shotshell, centerfire, and rimfire ammunition and components.
The 9.3×64mm Brenneke is a rimless bottlenecked centerfire rifle cartridge designed in 1927 by German gunmaker Wilhelm Brenneke. It is suitable for hunting medium to large game animals in Africa, Europe, and North America.
The following are terms related to firearms and ammunition topics.
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