Ammunition, often referred to as ammo, is a generic term derived from the French language la munition which embraced all material used for war (from the Latin munire, to provide), but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions. In the widest sense of the word it covers anything that can be used in combat that includes bombs, missiles, warheads, and mines (landmines, naval mines, and anti-personnel mines) – that munitions factories manufacture. The purpose of ammunition is predominantly to project force against a selected target. However, the nature of ammunition use also includes delivery or combat supporting munitions such as pyrotechnic or incendiary compounds. Since the design of the cartridge, the meaning has been transferred to the assembly of a projectile and its propellant in a single package.

The subject of ammunition is a complex one which covers application of fire to targets, general use of weapons by personnel, explosives and propellants, cartridge systems, high explosive projectiles (HE), warheads, Shaped charge forms of attack on armour and aircraft, carrier projectiles, fuzes, mortar ammunition, small arms ammunition, grenades, mines, pyrotechnics, improved conventional munitions, and terminally guided munition.

Glossary

• A Cartridge, is a single unit of ammunition; for a modern small arms cartridge this is the combination of bullet, propellant, primer and cartridge case in a single unit.
• A "round" is term synonymous with a fully loaded cartridge containing a projectile, propellent, primer and Casing.
• Large caliber cannons often fire explosive-filled projectiles known as shells, non-explosive projectiles may be used for practice (see artillery).
• A Gun is a cannon with a minimum 6-inch (155 mm) nominal bore diameter.
• 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 fully loaded ordnance that fail to function as intended. A cartridge that fails to fire in the weapon is known as a misfire. A partially functioning round is named a Hangfire(firearms). Dud ammunition is regarded as highly dangerous and also known as UXO, and most safety officials inform civilians to report finding of any large-bore duds to the local police or military.
• Dum-dum rounds are early attempts to cause contact-initiated expansion. Many were exposed Leadnose bullets with hashmarks cut across the nose in an "X" configuration.

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.