Military Wiki

The 20mm 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 20mm caliber, though the 14.5 mm caliber is used by some Soviet machineguns such as the KPV and antitank rifles such as PTRS, PTRD, and NTW-20.

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

20mm caliber cartridges have an outside shell diameter and inside barrel diameter of 0.79 inches (20 mm). Projectiles or shells are typically 75 to 127 mm (3–5 in) long. Cartridges are typically 75 to 152 mm (3–6 in) long. Many but not all 20mm shells have an explosive filling and detonating fuze.

As an example, the 20x102 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 x 102 mm round with .50 BMG rounds, golf ball, stick of RAM.

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

Types of ammunition

20 mm weapons

Each weapon is listed with its cartridge type appended.

Current weapons

Historical weapons

Cartridge type indicates the diameter of projectile and the length of the cartridge that holds it, for example 20x102 is a 20mm projectile in a 102mm 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


External links

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