20x82mm

20x82mm refers to a specific cartridge size, primarily associated with firearms. The designation indicates the projectile diameter and the length of the cartridge case. In this case, "20" represents a nominal bore or projectile diameter of 20 millimeters, and "82mm" signifies the length of the brass or steel case that holds the propellant and the projectile.

This cartridge size is not as common as many mainstream rifle or pistol calibers. Historically, 20mm rounds have been used in various applications, including anti-materiel rifles, autocannons, and some specialized infantry weapons designed for engaging lightly armored vehicles or fortifications. The larger diameter and case length generally translate to higher muzzle velocity and greater kinetic energy compared to smaller calibers, allowing for increased range and penetration.

A prominent example of a firearm chambered for a 20mm round is the South African NTW-20 anti-materiel rifle. These types of weapons are typically heavy and require specialized training for operation. The effectiveness of 20x82mm ammunition is dependent on the specific weapon it is fired from, the projectile type (e.g., armor-piercing, high-explosive, incendiary), and the intended target. Due to its power and size, it is not suitable for standard military service rifles or pistols.