Weapons Law Encyclopedia

Small arms ammunition

Gunpowder (also known in its early forms as black powder), is a mixture of charcoal, sulphur, and potassium nitrate (generally known as saltpetre). It was invented in China in the ninth century, and brought to Europe around the fourteenth century for use in cannons. Its power was increased in the fifteenth century when gunpowder started to be formed in small grains or ‘corns’, allowing for more rapid ignition.J. Bevan and S. Pézard, ‘Basic characteristics of ammunition: from handguns to MANPADS’, in: Pézard and Anders (eds.), Targeting Ammunition: A Primer, p. 18; W. H. McNeill, The pursuit of power: technology, armed force, and society since A.D. 1000, Basil Blackwell, Oxford, 1982, p. 88.

Up to the sixteenth century, firing a gun required bringing a source of fire into contact with the powder, usually a slow match.J. Ellis, The social history of the machine gun, Johns Hopkins University Press, Baltimore, 1975, p. 11. After that, the process was somewhat simplified by striking together a flint and roughened steel to produce a spark, and then with the invention of the percussion cap in 1807.

Early bullets were made of stone, then iron, then denser metals such as lead. These were initially spherical and loaded through the muzzle of unrifled smoothbore weapons. In the first half of the seventeenth century, kits combining both powder and a bullet in a tube of thick paper were made available. The shooter tore the paper apart, poured the powder into the muzzle of the weapon, and then inserted the bullet. The system allowed for quicker loading, and regulated the amount of powder used for every shot. The calibres of weapons were gradually reduced while engagement ranges increased.C. J. Marchant Smith and P. R. Haslan, Small Arms & Cannons, Battlefield Weapons Systems and Technology, Vol. 5, Brassey’s, Oxford, 1981, p. 33.

In 1848, what would become the Minié bullet was invented. This conical shape bullet – a revolutionary departure from the usual spherical bullets – had a hollow base into which an iron wedge was inserted. On firing, this wedge was driven into the base of the bullet, expanding the base. This property had a major advantage: bullets would then grip the rifling grooves of the bore, and seal the propellant gases behind, while being slightly smaller than the diameter of the bore for easy loading. Rifles had long existed but were very impractical for military use given the difficulty of muzzle-loading tightly fitting bullets. With the invention of the Minié bullet, for the first time, they became practical military weapons. Subsequent research found that the wedge could be eliminated with the same effect.Di Maio, Gunshot Wounds, p. 19.

The self-contained cartridge was invented in the mid-nineteenth century. It consisted of a single case holding a primer, propellant, and bullet. The cartridge was designed to be inserted whole into the breech of a weapon. Made of brass, it allowed a tighter seal within the weapon's barrel, which better contained the propellant gases and improved the weapons' range.

However, black (gun) powder still produced so much smoke that the infantry had to use volley fire.Marchant Smith and Haslan, Small Arms & Cannons, p. 33. It was also volatile, susceptible to moisture, and produced a lot of residue. In the late nineteenth century, the first smokeless propellant was invented. Smokeless powder was more powerful, easier to store, and less damaging to the weapons. In 1933, ball powder was invented by Winchester. Neither leaves significant residue in the bore.

The last quarter of the nineteenth century also saw the development of steel- or copper-jacketed bullets with a lead core. These were harder and more resistant to the heat in the barrel.

Last updated on: 10 February 2014

Classifying ammunition is difficult. One option is by calibre and cartridge case length. Small arms ammunition falls generally below 12.7mm calibre, even though sometimes the limit is placed at 14.5mm or even 20mm.Bevan and Pézard, ‘Basic characteristics of ammunition: from handguns to MANPADS’, , in: Pézard and Anders (eds.), Targeting Ammunition: A Primer, p. 23. Longer cases give more space for propellant and so are generally more powerful.

Airburst ammunition is also being developed for small arms.

Military calibres
 Type of weapons  NATO standards  Warsaw Pact standards
Assault rifles, light support weapons 5.56 x 45mm 7.62 x 39mm
Assault rifles, self-loading rifles, sniper rifles, light machine guns 7.62 x 51mm 7.62 x 54mm
Pistols 9 x 19mm Parabellum 7.62 x 25mm; 9 x 17mm
Heavy machine guns, sniper rifles, anti-materiel rifles 12.7 x 99mm 12.7 x 107mm; 12.7 x 114mm

Table sourceReproduced from: Bevan and Pézard, ‘Basic characteristics of ammunition: from handguns to MANPADS’, in: Pézard and Anders, Targeting ammunition: a primer, Small Arms Survey, Geneva, 2006, p. 27.

Non-military ammunition is more varied in calibre: small cartridges for concealed-carry pistols; specialist large-calibre pistol ammunition for hunting; match-grade rifle ammunition for target shooting; ammunition for marksmen in security forces; soft-nosed, low-velocity ammunition for law enforcement; armour-piercing and other larger calibres for big game hunting; or rubber or plastic rounds for riot or crowd control.Bevan and Pézard, ‘Basic characteristics of ammunition: from handguns to MANPADS’, p. 27.

The .45 ACP (Automatic Colt Pistol) is a common law enforcement pistol calibre.

Last updated on: 10 February 2014

It is difficult to speak of the impact of small arms without talking about ammunition: ‘It is the ammunition which does the damage and is the raison d'être of the small arm.’Marchant Smith and Haslan, Small Arms & Cannons, p. 1. The section on intended effects looks at the objective of ammunition design for military, law enforcement, and civilian uses. The section on humanitarian impact takes a closer look at wound ballistics. The aggregate effect of small arms use is discussed in the weapons entry on small arms.

Military uses

The normal target for small arms ammunition in military use is the human body, and the desired effect is that of a lethal or incapacitating wound. Any wound causing loss of consciousness, blindness or paralysis is considered incapacitating; however, other wounds can also qualify depending on the location of the wound, and the task and motivation of the wounded combatant (a wound in the foot is more likely to incapacitate an assaulting infantryman than a static defender, for example). Wounds also vary according to the time taken for them to become incapacitating.Marchant Smith and Haslan, Small Arms & Cannons, p. 20.

Only fully-jacketed bullets are permitted for military use.

Some type of small arms ammunition has also been developed to overcome hard targets. More energy is indeed needed when the target is protected by body armour, concrete slabs, a brick wall or other.Ibid., p. 38. Armour-piercing ammunition is generally of a larger calibre and has a hard steel core.

Law enforcement

Contrary to military use, police forces tend to adopt semi-jacketed bullets because they tend to ricochet less, and therefore pose less hazard to innocent bystanders in urban settings.Bevan and Pézard, ‘Basic characteristics of ammunition: from handguns to MANPADS’, p. 38.

Civilian uses

Semi-jacketed bullets are used in hunting because they increase the chance of a kill. Because their core is exposed at the top, they usually expand when they hit the target, leading to greater loss of kinetic energy and hence greater internal damage.Ibid.

Wound ballistics

By virtue of its motion, a projectile possesses kinetic energy, which is determined by the bullet's weight and velocity. When hitting a target, the bullet imparts kinetic energy to the surrounding tissue, flinging it away from the bullet's path in a radial manner. This produces a temporary cavity considerably larger than the diameter of the bullet (up to 30 times the diameter of the original bullet). Its size and shape depends on the amount of kinetic energy lost by the bullet, how rapidly the energy is lost, and the elasticity and cohesiveness of the tissue. When the cavity disappears, after 5 to 10 milliseconds, it leaves a permanent wound track. However, it is the temporary cavity that causes most of the wounding.Di Maio, Gunshot Wounds, p. 41–8.

Tissues rupture because the body cannot readily absorb energy. Energy is transferred to the target when the projectile loses velocity. The more energy is transferred, the more damage there will be.Marchant Smith and Haslan, Small Arms & Cannons, pp. 20–1.

While low velocity bullets (such as full metal-jacketed pistol bullets) rarely lose sufficient kinetic energy to cause injuries far from the bullet track, high velocity bullets are said to cause ‘explosive wounding’ because of the shock wave they create in the body. High velocity is a factor of muzzle velocity and of the loss of speed during the flight (itself influenced by the bullet's physical properties). If such bullets travel through the body without losing much speed, they will not create much damage. More damage is created if the bullet has less penetrating power, such as if it breaks up within the target, if it deforms on impact into a less streamlined shape, or if it becomes unstable when entering a denser medium than air.

Bullets produce damage through laceration and crushing of issue and bones in the direct path of the projectile, and via cavitation. The pressure applied by the temporary cavity on surrounding tissues and organs provokes injuries far from the bullet path and therefore hard to detect, particularly to soft organs. It is also capable of fracturing bones several centimetres from the bullet track.E. Prokosch, The Technology of Killing: A military and political history of antipersonnel weapons, Zed Books, London and New Jersey, 1995, pp. 18–9; Di Maio, Gunshot Wounds, p. 43. Foreign material and bacteria are also sucked into the wound track from both the entrance and exit.

The extent of injury also depends on the angle of yaw of the bullet. If the path of the bullet through tissue is long enough, instability will increase until the bullet tumbles end-over-end.Di Maio, Gunshot Wounds, p. 47. If the bullet fragments, each fragment will follow a distinct path, thereby multiplying the effect of a single bullet.Prokosch, The Technology of Killing, pp. 191–2.

Other health impacts

Immediate impacts from gunshots include soft tissue injuries, bone fractures, and vital organ damage. Injuries to extremities often result in fractures, which if left untreated, may lead to haemorrhages and infections or to permanent disability due to joint or bone deformities.C. Buchanan and M. Widmer (eds.), Missing Pieces: A guide for reducing gun violence through parliamentary action, Centre for Humanitarian Dialogue and Inter-Parliamentary Union, Geneva, 2007, p. 65. Brain and spinal cord injuries are more difficult to treat, leaving irreversible damage such as paralysis, sexual dysfunction, limited movement, seizure disorders, incontinence, and severe facial disfigurations.

Injuries and disabilities sustained through gun violence are also associated with psychological problems and can result in flashbacks, anxiety and fear, self-destructive behaviours, low self-esteem, depression, suicidal behaviour and action, and alienation from friends and family.

Last updated on: 10 February 2014

Applicable international, regional & national law

2001 Firearms Protocol

The UN Protocol against the Illicit Manufacturing of and Trafficking in Firearms, Their Parts and Components and Ammunition (2001 Firearms Protocol) was the first global, legally binding instrument on small arms control. It contains important provisions on manufacturing, marking and tracing, record-keeping, and international transfers of firearms.

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2013 Arms Trade Treaty

The 2013 Arms Trade Treaty (ATT) is the first global, legally binding instrument regulating international transfers of most conventional weapons, as well as some ammunition / munitions, and parts and components.

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