Ammunition
Ammunition is a generic term meaning (the assembly of) a projectile and its propellant. It is derived through French from the Latin munire (to provide). See also munition.
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Glossary
- Small projectiles, like those fired from rifles and handguns (collectively known as small arms), are called bullets.
- A "round" is a single unit of ammunition; for small arms this is the combination of bullet, propellant, primer and cartridge case.
- Large caliber guns often fire explosive-filled projectiles known as shells, the equivalent non-explosive projectile is a shot (see artillery).
- Large numbers of small projectiles intended to be fired all at once in a single discharge are also called shot; hand-held guns designed for this type of ammunition are generally known as shotguns.
- Duds are ammunition that fail to work as intended.
General information
The design of the ammunition is determined by its purpose; anti-personnel ammunition is often designed to break up or tumble inside the target, in order to maximize the damage done. Anti-personnel shells contain shrapnel and are designed to explode in mid-air, so its fragments will spread over a large area. Armor-piercing ammunition tends to be hard, sharp, and narrow, often with lubrication. Incendiary projectiles include a material such as white phosphorus which burns fiercely. Tracer ammunition emits light as it travels, allowing the gunner to see the path of bullets in flight while using a machine gun.
Popular types of military rifle and machine-gun ammunition include the 5.45 mm, 5.56 mm, and 7.62 mm. Main battle tanks use KE-penetrators to combat other MBTs and armoured fighting vehicles, and HE-Frag (High Explosive-Fragmentation) for soft targets such as infantry.
Ammunition, particularly that of small arms, is specified by an extremely wide range of designations derived from metric and English measurements, commercial firms' private systems, and the different requirements of armies of different countries. German firms in the late twentieth century have decided to make "all-metric" ammunition, a refinement of existing designs.
Match-grade ammunition is of exceptional quality and consistency, intended for target-shooting competition.
The components of ammunition intended for rifles and ordnance may be divided into these categories:
- explosives and propellants
- projectiles of all kinds
- cartridges
Storage
Historical (circa World War I)
These general conditions apply to the storage of ammunition in fortresses. Here the positions for the magazine and ammunition stores are so chosen as to afford the best means of protection from an enemy's fire. Huge earth parapets cover these buildings, which are further strengthened, where possible, by traverses protecting the entrances. For the purpose of filling, emptying, and examining cannon cartridges and shell, a laboratory is generally provided at some distance from the magazine. The various stores for explosives are classified into those under magazine conditions (such as magazines, laboratories, and cartridge stores) and those with which these restrictions need not be observed (such as ammunition and shell stores). The interior walls of a magazine are lined, and the floors laid so that there may be no exposed iron or steel. At the entrance, there is a lobby or barrier, inside which persons about to enter the magazine change their clothes for a special suit, and their boots for a pair made without nails. In an ammunition or shell store these precautions need not be taken except where the shell store and the adjacent cartridge store have a common entrance; persons entering may do so in their ordinary clothes. A large work may have a main magazine and several subsidiary magazines, from which the stock of cartridges is renewed in the cartridge stores attached to each group of guns or in the expense cartridge stores and cartridge recesses. The same applies to main ammunition stores which supply the shell stores, expense stores, and recesses.
The supply of ammunition are either for guns forming the movable armament or for guns placed in permanent positions. The movable armament will consist of guns and howitzers of small and medium caliber, and it is necessary to arrange suitable expense cartridge stores and shell stores close to the available positions. They can generally be constructed to form part of the permanent work in the projected face of traverses or other strong formations, and should be arranged for a twenty-four hour supply of ammunition. These stores are refilled from the main magazine every night under cover of darkness. Light railways join the various positions. The guns mounted in permanent emplacements are divided into groups of two or three guns each, and usually each group will require but one calibre of ammunition. A cartridge store, shell store and a general store, all well ventilated, are arranged for the especial service of such a group of guns. In the cartridge store the cylinders containing the cartridges are so placed and labeled that the required charge, whether reduced or full, can be immediately selected.
In the shell store the common shell are separated from the armour-piercing or shrapnel. Each nature of projectile is painted in a distinctive manner to render identification easy. The fuzes and tubes are placed in the general store with the tools and accessories belonging to the guns. The gun group is distinguished by some letter and the guns of the group by numerals; thus A/1 is number one gun of group A. The magazine and shell stores are also indicated by the group letter, and so that mistakes, even by those unaccustomed to the fort, may be avoided, the passages are pointed out by finger posts and direction boards. For the immediate service of each gun, a few cartridges and projectiles are stored in small receptacles (called cartridge and shell recesses respectively) built in the parapet as near the gun position as practicable. In some cases, a limited number of projectiles may be placed close underneath the parapet if this is conveniently situated near the breech of the gun and not exposed to hostile fire.
In order to supply the ammunition sufficiently rapidly for the efficient service of modern guns, hydraulic, electric, or hand-power, hoists are employed to raise the cartridges and shell from the cartridge store and shell store to the gun floor, whence they are transferred to a derrick or loading tray attached to the mounting for loading the gun.
Projectiles for BL guns above 6 inch (152 mm) calibre are stored in shell stores ready filled and fuzed standing on their bases, except shrapnel and high-explosive shell, which are fuzed only when about to be used. Smaller sizes of shells are laid on their sides in layers, each layer pointing in the opposite direction to the one below to prevent injury to the driving bands. Cartridges are stored in brass corrugated cases or in zinc cylinders. The corrugated cases are stacked in layers in the magazine with the mouth of the case towards a passage between the stacks, so that it can be opened and the cartridges removed and transferred to a leather case when required for transport to the gun. Cylinders are stacked, when possible, vertically one above the other. The charges are sent to the gun in these cylinders, and provision is made for the rapid removal of the empty cylinders.
The number and nature of rounds allotted to any fortress depends on questions of policy and location, the degrees of resistance the nature of the works and personnel could reasonably be expected to give, and finally on the nature of the armament. That is to say, for guns of large calibre three hundred to four hundred rounds per gun might be sufficient, while for light QF guns it might amount to one thousand or more rounds per gun.
Modern era
Modern ammunition includes not only shells for tube artillery and mortars, but increasingly aircraft-delivered bombs, smart bombs, rockets and other explosive-bearing projectiles. The destructive power and lethality of these systems is difficult to appreciate. A single cluster bomb, deliverable by any of the above systems, can sow grenade-sized bomblets across a 100 yard (90 m) football-sized field in sufficient density to kill any persons present, even in trenches and wearing body armor.
See ammo dump for discussion of modern ammunition storage facilities.
Supply of ammunition in the field
With every successive improvement in military arms there has necessarily been a corresponding modification in the method of supplying ammunition and in the quantity required to be supplied. When hand-to-hand weapons were the principal implements of battle, there was no such need. But in the Middle Ages, the archers and crossbowmen had to replenish the shafts and bolts expended in action, and during a siege, stone bullets of great size, as well as heavy arrows, were freely used. The missiles of those days were however interchangeable, and at the battle of Towton (1461), part of the War of the Roses, the commander of the Yorkist archers induced the enemy to fire arrows in order to obtain them for firing back. This interchangeability of war material was even possible for many centuries after the invention of firearms. At the battle of Liegnitz (1760) a general officer was specially commissioned by Frederick the Great to pack up and send away, for Prussian use, all the muskets and ammunition left on the field of battle by the defeated Austrians.
Captured material is utilized whenever possible at the present time. In the First Sino-Japanese War, the Japanese went so far as to prepare beforehand spare parts for the Chinese guns they expected to capture. Though it is rare to find a modern army trusting to captures for arms and ammunition; almost the only instance of the practice is that of the Chilean Civil War (1891) in which the army of one belligerent was almost totally dependent upon this means of replenishing stores of arms and cartridges. But what was possible with weapons of comparatively rough make is no longer to be thought of in the case of modern arms.
The Lee-Metford bullet of 0.303 inch (7.7 mm) diameter can scarcely be used in a rifle of smaller caliber, and in general the minute accuracy of parts in modern weapons makes interchangeability almost impossible. Further, owing to the rapidity with which, in modern arms, ammunition is expended, and the fact that, as battles are fought at longer ranges than formerly, more shots have to be fired in order to inflict heavy losses, it is necessary that the reserves of ammunition should be as close as possible to the troops who have to use them. This was always the case even with the older firearms, as, owing to the great weight of the ammunition, the soldier could only carry a few rounds. Nevertheless it is only within the past seventy years that there has grown up the elaborate system of ammunition supply which now prevails in all regularly organized armies. That which is described in the present article is the British, as laid down in the official Combined Training (1905) and other manuals. The new system designed for stronger divisions, and others, vary only in details and nomenclature.
Ammunition for infantry
Ammunition for infantry refers to the ammunition carried by a typical foot (infantry) soldier. Someone serving in the infantry generally carries, in pouches, bandoliers, etc., one hundred rounds of small-arms ammunition (S.A.A.), and it is usual to supplement this, when an action is imminent, from the regimental reserve (see below). Like any trade, the proper tools are necessary for the task at hand. Infantry need to be provided with the weapons and ammunition to deal with the expected threat, be it another foot soldier, a mounted warrior, armoured vehicle or aircraft.
History
Every reduction in the caliber (size) of the rifle's ammunition means an increase in the number of rounds carried. One hundred rounds of the Martini-Henry ammunition weighed 10 pounds 10 ounces (4.8 kg); the same weight gives 155 rounds of 0.303 in (7.7 mm) ammunition and at 0.256 in (6.5 mm) the number of rounds is still greater. The regimental reserves were historically carried in six S.A.A. carts and on eight pack animals. The six carts are distributed, one as reserve to the machine gun, three as reserve to the battalion itself, and two as part of the brigade reserve, which consists therefore of eight carts. The brigade reserve communicates directly with the brigade ammunition columns of the artillery (see below). The eight pack animals follow the eight companies of their battalion. These, with two out of the three battalion carts, endeavour to keep close to the firing line, the remaining cart being with the reserve companies. Men also are employed as carriers, and this duty is so onerous that picked men only are detailed. Gallantry displayed in bringing up ammunition is considered indeed to justify special rewards. The amount of S.A.A. in regimental charge is 100 rounds in the possession of each soldier, 2000 to 2200 on each pack animal, and 16,000 to 17,600 in each of four carts, with, in addition, about 4000 rounds with the machine gun and 16,000 more in the fifth cart.
Current small arms ammunition
Currently, every army of an internationally recognized country (except those who rely on others for defense, such as Andorra, and those that do not have a true army, such as the Vatican City) has adopted assault rifles as the main infantry weapon.
In western (NATO) forces, the 7.62 mm NATO round has been mostly replaced by the lighter 5.56 mm NATO round, which is better suited for automatic fire than the larger round and allows each soldier to carry more ammunition. The larger caliber ammunition is still retained where range and weight of shot is important eg machine guns and sniper rifles.
Other nations, especially forces with former ties to the Soviet Union tend to use rifles related to or devleoped from the AK-47 with similar sized rounds to the NATO ones. In 7.62x39mm and 5.45x39mm for assault rifles and 7.62x54R for sniper rifles and light machine guns.
Anti-tank
The tank made horse mounted cavalry obsolete and while an infantryman could deal with a horse-borne enemy new weapons were needed to damage a tank or other vehicle or penetrate and wound the crew. The first anti-tank weapons given to infantry were based on small arms, for example the anti-tank rifle. As even the lighter designs of tank carried more armour the limit of a man-portable rifle that could fire a round with sufficient kinetic energy to penetrate the armour was reached. The introduction of the shaped charge warhead gave the infantry a weapon that used chemical energy rather than kinetic to beat the armour and in a focussed way which made them more effective than large grenades. When propelled by a rocket, the shaped charge gained range as well. Weapons such as the Bazooka or Panzerfaust were never small but they were suitable for infantry use - though they often had to be used at close range where they could be aimed accurately at the vehicles weak points. Post World War 2, the advent of the missile delivered both great range and accuracy and provided infantry with a weapon that could reliably destroy the heaviest tanks at long distances.
Anti-aircraft
Today's infantryman can deploy sophisticated multi-spectral man-portable surface-to-air missiles equipped with the ability to reject decoys and defeat counter-measures. In Somalia it was demonstrated that slow moving/stationary aircraft at low altitudes could be defeated with unguided anti-armour infantry weapons. It is also true that aircraft are relatively delicate machines, filled with highly flammable fuel, and since their first usage in World War I a plane can be brought down by single bullet striking something vital. The main weaknesses of ammunition provided to infantry to deal with aircraft are limited range and small warheads, both due to the necessity that such weapons remain portable by men on foot. The premier SAM for infantry is the FIM-92 Stinger MANPADS (Man Portable Air Defence System), provided as an all-up round in a canister it is attached to a launcher unit and is ready to expend. Numerous other missiles in this class exist from different nations of origin. Infantry machine guns and rifles may improve their ability against aircraft by utilising tracer ammunition, to allow the aimer to better gauge the lead aim necessary to strike his target. Weapons developed primarily for anti-tank roles can add proximity fusing to increase the probability of a kill by having the warhead detonate nearby the target without having to make contact.
Large weapon ammunition
See Main article, Shell (projectile), for information on the various types of shell and shot.
Modern artillery ammunition is generally of two types: separate loading and semi-fixed. Semi-fixed ammunition (rounds) appear in the form of a projectile mated with a cartridge case which contains the propellant and they resemble small arms rounds.
The canister is outfitted with a primer on its base which fires upon contact from the firing pin. Gunpowder, precision machined to burn evenly, is contained inside of cloth bags that are numbered. US/NATO 105 mm howitzers use semi-fixed ammunition, containing seven powder bags referred to as increments or charges. Putting the powder in bags allows the howitzer crew to remove the increments when firing at closer targets. The unused increments are disposed of by burning in a powder pit at a safe distance from the guns.
Above a certain size, semi-fixed rounds are impracticable; the weight of the whole assembly is too much to be carried effectively. In this case separate loading ammunition is used: the projectile and propelling charge are supplied and loaded separately. The projectile is rammed home in the chamber, the powder charge(s) are loaded (usually by hand), then the breech is closed and the primer is inserted into the primer holder on the back the breech. Separate loading ammunition is typically used on 155 mm and larger howitzers. Several propellant types are available for 155 mm howitzer.
All normal projectiles arrive at the weapon with a plug in the fuze well on the nose of the projectile. Using a special fuze wrench, the plug is unscrewed and a fuze is screwed in. The decision as to which type of fuze to use is made by the fire direction center and carried out by the gun crew.
The armaments fitted to early tanks were contemporary field or naval artillery pieces and used the same ammunition. When tank versus tank combat became more important, the trend became that anti-aircraft artillery pieces (designed to fire high velocity shells to altitude) were often adapted to tank use where a gun specifically made for the vehicle was not available. As the armour applied to tanks increased, ammunition for tank use paralleled that of anti-tank guns. Current tank gun ammunition is a single fixed round ("shell" and charge combined in a single piece) for quick load, the charge is in a combustible case - so there is no empty cartridge to be removed and stored in the turret and the "shell" is a saboted shot, a shaped charge or sensor fuzed warhead.
Naval ammunition
The ranges at which engagements are conducted by warships are typically much greater than that at which land warfare is observed. The targets are also generally machines, not men. Naval ammunition is therefore optimized for great velocity (to reach those great ranges, to hit aircraft flying at altitude and also with the benefit of reducing the lead that has to be applied to hit a distant moving target) and to disable said machines, rather than rending human flesh. Naval gun ammunition of WWII vintage came in two main varieties, armour piercing shells to attack hardened warships or high explosive incendiary shells (with point detonating fuzes to start fires on ships, or mechanical time fuzes designed to fragment and create clouds of shrapnel to defeat aircraft). With the demise of the armoured warship, contemporary naval gun ammunition is solely the high explosive variety, but new fuzing and guidance options are available to increase lethality, especially against high speed missile or aircraft threats.
Fuzes
Common artillery fuses include point detonating, delay, time, and proximity (variable time). Point detonating fuses detonate upon contact with the ground. Delay fuzes are designed to penetrate a short distance before detonating. Time fuzes, as the name implies, detonate a certain time after being fired in order to achieve an air burst above the target. Time fuzes are set to the tenth of a second. Proximity or variable time fuzes contain a simple radio transceiver activated a set time after firing to detonate the projectile when the signal reflected from the ground reaches a certain strength, designed to be 7 meters above the ground. Fuses are armed by the rotation of the projectile imparted by the rifling in the tube, and usually arm after a few hundred rotations.
See also
- List of rifle cartridges
- List of handgun cartridges
- Ammunition column
- Reloading
- Rotation of ammunition
- Armor-piercing shot and shell
- Teflon coated bullet
- Hollow point bullet
- Full metal jacket bullet
- Rheological Ammunition
- Dum dum
- Explosive
- High Explosive Incendiary
- Ammo dump
- Tracer ammunition
- Fuze for ammunition
- Proximity fuze
- Tubes and primers for ammunition
- Bullet
- Cartridge (firearms)
- Howitzer
- Shell (projectile)
- Hatton round
References
- This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.
