Artillery Projectile

a type of ammunition designed to be fired from a cannon, mortar, or rocket artillery; a component of an artillery round.

An artillery projectile consists of a casing, a filler—the bursting charge or tracer—and a fuze. Rocket-assisted and rocket artillery projectiles have, in addition, a solid-propellant engine; some artillery projectiles are also equipped with a stabilizer. The casing is constructed of alloy steel or semisteel and consists of an ogive, a cylindrical body, and a base. To guide the projectile along the bore during firing, the cylindrical part has one or two bourrelets and a rotating band (made of copper, laminated metal, ferroceramic, or nylon), which is pressed into a groove. The rotating band prevents the escape of the propellant gases and imparts to the projectile the rotatory motion necessary for stability in flight.

The length of a cannon shell is 2.3 to 5.6 times greater than the diameter of the shell (caliber). The length of a mortar shell may be up to eight times longer than the caliber, and that of a rocket artillery projectile, 5.5 to 10.7 times longer. Weights vary from 0.1 to 133 kg for cannon shells, from 1.3 to 131 kg for mortar shells, and from 11 to 194 kg for rocket artillery projectiles. A mortar shell consists of a teardrop-shaped casing, a stabilizer, a bursting charge, and a fuze.

Artillery projectiles are classified as ordinary, rocket, or rocket-assisted projectiles. Ordinary projectiles receive motion as a result of the energy of the propellant gases in the bore of the cannon or mortar. Rocket projectiles, used in rocket artillery, are equipped with a rocket engine. In rocket-assisted projectiles, used for cannons and mortars, the propellant gases created during the combustion of the ordinary charge drive the projectile out of the bore, while the rocket charge, which burns while the projectile is in flight, imparts additional velocity.

Artillery projectiles are classified according to military purpose as basic, special, or auxiliary. The basic category includes fragmentation, high-explosive, high-explosive-fragmentation, and concrete-piercing shells. Such shells destroy targets with the fragments from the exploding projectile casing or through the force of the gases from the exploding projectile or the force upon the projectile’s impact on an obstacle. The basic category also includes shrapnel and other projectiles filled with destructive elements and armor-piercing projectiles. The latter destroy targets by the penetration effect, which depends on the kinetic energy of the projectile at the moment of impact with an armored target and on the angle of impact. Moreover, the after-armor effect is created by the impact, high-explosive, fragmentation, and incendiary actions. Other basic projectiles include high-explosive antitank projectiles, which destroy armored targets by the shaped-charge jet formed at the moment of detonation, and incendiary projectiles, which destroy targets by means of an incendiary mixture that upon burning develops temperatures up to 3000°C. The armies of foreign governments have chemical projectiles that destroy personnel and contaminate the air, terrain, and food and water; they also have nuclear projectiles that destroy targets by means of a shock wave, penetrating radiation, and thermal radiation.

Among the special projectiles are smoke, illuminating, and propaganda (leaflet) shells. Such projectiles are used for illuminating enemy-held terrain, for blinding the enemy, for adjusting the range of artillery pieces, for designating targets, and for dropping propaganda literature into the enemy’s position. Auxiliary projectiles are used for troop combat training and in proving-ground tests.

Artillery projectiles are classified according to caliber as small (20–70 mm), medium (70–155 mm for ground artillery and up to 100 mm for antiaircraft cannon), and large (more than 155 mm for ground and more than 100 mm for antiaircraft artillery).

Artillery projectiles may also be classified according to the relationship between the outside diameter of the projectile and the diameter of the bore as full-caliber, subcaliber, or supercaliber projectiles. In a full-caliber projectile, the diameter of the projectile is equal to the diameter of the bore. In a subcaliber projectile, the diameter of the destructive part of the projectile—the core—is smaller than the diameter of the bore; consequently such projectiles must be equipped with jacketing that corresponds to the caliber of the weapon and guides the projectile along the bore. In a supercaliber projectile, the diameter of the projectile is larger than the caliber of the weapon; the base of such a projectile is inserted into the gun barrel.

The effectiveness of a projectile depends on the type and weight of the filler and is a function of the ratio of the weight of the filler to the total weight of the projectile, which for high-explosive projectiles reaches 25 percent, for high-explosive-fragmentation and hollow-charge projectiles 15 percent, and for armor-piercing projectiles 2.5 percent. The effectiveness of fragmentation projectiles is also dependent on the number of lethal fragments and the radius of the area under fire. Projectiles are also characterized by their maximum effective range (or maximum altitude capability), accuracy of fire, handling safety, and stability in storage. A unit of fire usually includes cannon and mortar shells of various purposes and designs.