Tank gun

A tank gun is the main armament of a tank. Modern tank guns are large-caliber high-velocity guns, capable of firing kinetic energy penetrators, high explosive anti-tank rounds, and in some cases guided missiles. Anti-aircraft guns can also be mounted to tanks.

As the tank's primary armament, they are almost always employed in a direct fire mode to defeat a variety of ground targets at all ranges, including dug-in infantry, lightly armored vehicles, and especially other heavily armored tanks. They must provide accuracy, range, penetration, and rapid fire in a package that is as compact and lightweight as possible, to allow mounting in the cramped confines of an armored gun turret. Tank guns generally use self-contained ammunition, allowing rapid loading (or use of an autoloader). They often display a bulge in the barrel, which is a bore evacuator, or a device on the muzzle, which is a muzzle brake.

History

World War I

Tank

A tank is a large, heavily armoured fighting vehicle with tracks and a large tank gun that is designed for front-line combat. Modern tanks are mobile land weapon platforms, mounting a large-calibre cannon in a rotating gun turret. They combine this with heavy vehicle armour which provides protection for the crew, the vehicle's weapons, and its propulsion systems, and operational mobility, due to its use of tracks rather than wheels, which allows the tank to move over rugged terrain and be positioned on the battlefield in advantageous locations. These features enable the tank to perform well in a tactical situation: the combination of powerful weapons fire from their tank gun and their ability to resist enemy fire means the tank can take hold of and control an area and prevent other enemy vehicles from advancing. In both offensive and defensive roles, they are powerful units able to perform key primary tasks required of armoured units on the battlefield. The modern tank was the result of a century of development from the first primitive armoured vehicles, due to improvements in technology such as the internal combustion engine, which allowed the rapid movement of heavy armoured vehicles. As a result of these advances, tanks underwent tremendous shifts in capability during the World Wars of the 20th century.

Gun

A gun is a normally tubular weapon or other device designed to discharge projectiles or other material. The projectile may be solid, liquid, gas or energy and may be free, as with bullets and artillery shells, or captive as with Taser probes and whaling harpoons. The means of projection varies according to design but is usually effected by the action of gas pressure, either produced through the rapid combustion of a propellant or compressed and stored by mechanical means, operating on the projectile inside an open-ended tube in the fashion of a piston. The confined gas accelerates the movable projectile down the length of the tube, imparting sufficient velocity to sustain the projectile's travel once the action of the gas ceases at the end of the tube or muzzle. Alternatively, acceleration via electromagnetic field generation may be employed in which case the tube may be dispensed with and a guide rail substituted.

The first devices identified as guns appeared in China around CE 1000. By the 12th century the technology was spreading through the rest of Asia, and into Europe by the 13th century.

20 mm caliber

The 20 mm caliber is a specific size of cannon or autocannon ammunition.

There are few weapons (aside from shotguns and large game hunting rifles) which have been built that fire projectiles between .50 caliber (0.50 inches/12.7 mm, roughly 13 mm caliber) and 20 mm caliber, though the 14.5 mm caliber is used by some Soviet machineguns such as the KPV and anti-tank rifles such as PTRS, PTRD, and NTW-20.

A very small number of anti-tank rifles have been produced in 20 mm and larger calibers.

20 mm caliber cartridges have an outside bullet diameter and inside barrel diameter of 0.787 inches (20.0 mm). Projectiles or bullets are typically 75 to 127 mm (3–5 in) long. Cartridge cases are typically 75 to 152 mm (3–6 in) long. Many but not all 20 mm rounds have an explosive filling and detonating fuze.

As an example, the 20×102mm has a 100-gram bullet fired at a muzzle velocity of 1,035 m/s (3,396 ft/s). For a simple slug round this is a muzzle energy of 53,567 joules (39,509 ft·lbf).

Usage

M1128 Mobile Gun System

The M1128 Mobile Gun System is an eight-wheeled armored car of the Stryker armored fighting vehicle family, mounting a 105 mm tank gun, based on the Canadian LAV III light-armored vehicle manufactured by General Dynamics Canada. It is in service with the United States and was also being considered for adoption by several other countries, including Canada.

Design

Firepower

The MGS' remote weapon-station has a small silhouette, is stabilized and autoloading. The remote weapon-station mounts a 105 mm M68A2 rifled cannon. The vehicle is primarily outfitted to support infantry combat operations. While it could take on some of the roles of tanks, it is not designed to engage in combat with tanks. The MGS can store 18 rounds of main gun ammunition in the turret. It has a rate of fire of six rounds per minute.

The MGS' 105 mm cannon can fire four types of ammunition: the M900 kinetic energy penetrator to destroy light armored vehicles; the M456A2 high explosive anti-tank round to destroy thin-skinned vehicles and provide anti-personnel fragmentation; the M393A3 high explosive plastic round to destroy bunkers, machine gun and sniper positions, and create openings in walls for infantry to access; and M1040 canister shot for use against dismounted infantry in the open.