Antiaircraft Machine-Gun Installation

an automatic weapon consisting of one or several (usually two to four) machine guns mounted on a special carnage with shared laying mechanisms and sighting devices for antiaircraft fire. They appeared in the 1930’s and were designed for the air defense of ground forces and ships. They can also be used against lightly armored ground and above-water targets. Units of the ground forces, some tanks and other combat vehicles, and also small ships are armed with antiaircraft machine guns. They are found in the armies of various states. In antiaircraft units, antiaircraft machinegun installations are transported on two-axle cariages towed by motor vehicles. The caliber of the machine guns is 12.7–14.5 mm, the slant range of firing is up to 2,500 m, the rate of fire of one barrel is 500–600 rounds a minute, and the elevation angle is up to 90° and the transverse angle up to 360°. The guns fire primarily armor-piercing incendiary bullets, either from brief halts or while in motion; the bullets weigh 45–65 g and their muzzle velocity is 900–1,000 m/sec.