20 mm caliber

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"20mm" redirects here. For the model scale, see List of scale model sizes.

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).


20×102mm round with .50 BMG rounds, golf ball, stick of SDRAM computer memory.

Like most cannon ammunition, 20 mm caliber weapons are typically used against large targets such as vehicles, buildings, or aircraft. Though lethal against individual soldiers, 20 mm ammunition is so large and heavy that its effects are inefficient against relatively small targets.

Types of ammunition[edit]

20 mm weapons[edit]

Each weapon is listed with its cartridge type appended.

Current weapons[edit]

Historical weapons[edit]

Cartridge type indicates the diameter of projectile and the length of the cartridge that holds it; for example 20×102mm is a 20 mm projectile in a 102 mm long case. Only rarely do two designers use the same case length, so this designation is usually definitive. Some cartridge types have additional letters or information about them listed.

See also[edit]


External links[edit]