and pressed into finished shape. The cases usually have a rim around the base, but some have a groove, called a cannelure, sunk into and surrounding the base; the chief use of both rim and cannelure is to enable the extractor to take hold of and extract the empty case after firing; but the rim also assists to hold the case in its proper position in the gun. The high velocity given the projectile in a modern gun entails the use of a relatively large charge of powder; to hold this, and to avoid undue length of case, which involves unnecessary weight and introduces difficulties in connection with vibrations and pressures, the case is increased in diameter over the powder and drawn down to form a bottle-neck where it grips the projectile. No paper cases are used for military or naval arms, but the cases for the ammunition of breech-loading shot-guns have the cylindrical portion of cardboard or papier-maché, the base being of brass formed in the manner already described.
Gunpowder (see Explosives and Gunpowder), the propelling force in all military weapons in general service (except pneumatic guns, which have a very limited use and are not generally approved for any purpose), is put up, for guns of large calibre, in bags made of some sort of cloth, usually serge. For convenience of handling, the charges are divided into sections when the weight of the full charge exceeds one hundred pounds. Powder charges, when in bags, are stowed in water-tight copper tanks in compartments or buildings called magazines; on shipboard, magazines are placed below the water line, near the bottom of the ship, and as far away as practicable from the heat of boilers and engines. In fortifications the magazines for war service are below ground or behind ample protections. Fixed ammunition is stored in rooms similar to magazines, as are also projectiles (q.v.). Powder charges, whether in metallic cases or in bags, are ignited by primers; these are of four types: percussion, friction, electric, and combination (percussion and electric). Percussion primers resemble miniature fixed ammunition; those used in the United States Navy are about an inch long, one-fifth of an inch in diameter in the body, and enlarged considerably at the base; they contain seven grains of fine powder in the body, and a primer cap in the head, which will ignite when struck by the firing pin of the gun lock. Friction primers are of the same shape and size, but are ignited by the friction caused by drawing a serrated strip of metal through the fulminate in the primer head. Their use in the United States Navy has been discontinued, but they are still in some favor abroad. Electric primers differ from those already mentioned in being ignited by an electric spark instead of by friction or percussion. Single and double wire systems are employed, but only the former is used in the United States Navy; in guns which do not use fixed ammunition the current, furnished by a dry battery, or the dynamo, passes through a single insulated copper wire into the primer; there it encounters resistance in the shape of a bridge of platinum wire, and thence escapes through the metal of the primer to the gun and so to earth; in passing through the platinum bridge it heats the latter white hot and thus causes ignition. In guns using fixed ammunition, the electric primer is screwed or pressed into the base of the powder case; the current enters the primer through the electric primer connection, which is similar to the percussion firing pin, but is insulated in order to carry the current. The combination primer is being experimented with in Europe; in the United States Navy it is displacing the percussion and electric primers, as all new guns and powder cases are fitted to take it, and the old ones are being altered as opportunity offers. It may be ignited either by an electric current or by percussion. It is much larger than the older primers, being about two inches long and about as large around as a lead pencil.
Effective ammunition is one of the most important factors of modern warfare, and the one great factor in determining prevailing tactics, methods of defense, and equipment of men and materials. Every improvement in rapidity of fire of weapons increases the anxiety about the supply of ammunition in the field; nevertheless, it must be remembered that, although separate battalions or batteries have on occasion been without ammunition, the troops as a whole have never suffered from this want. The soldier carries a considerable number of rounds on his person, and at the very opening of a battle the company ammunition wagons are available; when they are exhausted, they go to the nearest ammunition column, replenish, and return as quickly as possible. The field artillery uses its limber ammunition only when no other is available, that of the caissons being used first; the empty caissons being replaced by others from the second échelon of the battery, and the latter obtaining further supplies from the ammunition columns.
The question of ammunition was one of the subjects of the Peace Congress held at The Hague in the summer of 1899, and strong recommendations were made to discountenance the use of explosive or expanding bullets. The English in the Sudan, and in smaller Indian punitive expeditions, found that the smallness, shape, and velocity of a modern rifle bullet had not a sufficiently deterring effect on the charging masses of tribesmen, and frequently used the so-called dum-dum bullet, which is made of softer metal and expands or contracts. During the Boer War dum-dum and explosive cartridges were frequently found after the various battles, each side charging the other with having used them. In the Spanish-American War of 1898-99 the small, clean-cut wounds caused by the Krag-Jörgensen (United States) and Mauser (Spanish) bullets were found fatal only in a small percentage of cases. Instances were frequent where men continued to fight for some time after being hit.
In England, and Europe generally, all government-made ammunition is manufactured at the government arsenals. See Arsenal.
The word ammunition is still retained in the English services in its early English form, as pertaining to certain forms of military supplies; ammunition shoes, ammunition socks, ammunition bread, ammunition shirts, etc., as distinct from the same articles supplied from purely civil sources. See Projectile; Fuze; Primer; Cartridge; Ordnance; Artillery, etc.
AMMUNITION CHESTS. Boxes containing ammunition, packed so as to be fitted for transport by either elephant, camel, bullock, pack-horse or mule; or in the case of horse and field artillery so arranged that the gunners may utilize them for seats or pack them in caissons.
