20 mm caliber


20 mm refers to a common firearms bore diameter, typically used for cannon or autocannons. 20 mm cartridges have an outside bullet diameter and inside barrel diameter of. Projectiles are typically long. Cartridge cases are typically long and most are shells, with an explosive filling and detonating fuze.
Weapons using this calibre range from anti-materiel rifles and anti-tank rifles to aircraft autocannons and anti-aircraft guns.

Usage

20 mm caliber weapons are generally not used to target individual soldiers, but against targets such as vehicles, buildings, or aircraft.

Types of ammunition

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 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.