The MG 131 (shortened from German: Maschinengewehr 131, or "machine gun 131," and occasionally written as MG 131/13, particularly in German sources) was a German 13 mm caliber machine gun developed in 1938 by Rheinmetall-Borsig and produced from 1940 to 1945. The MG 131 was designed for use at fixed, flexible or turreted, single or twin mountings in Luftwaffe aircraft during World War II. It was also license-built in Japan for the Imperial Japanese Navy as Type 2 machine gun.

Overview

The MG 131 was one of the smallest and lightest of the heavy machine guns of its era, with a weight of 16.6 kilograms (37lb). This was less than 60% of the M2 Browning or the Breda-SAFAT machine gun while still providing rapid fire and heavy firepower for its mass. It could fire armor-piercing, incendiary, high-explosive, and tracer ammunition. The other main Axis automatic weapon of similar caliber, the Italian Breda 12.7mm was around 13kg heavier and bigger, while slower by at least 150 rpm. The MG 131's relatively small size allowed them to be mounted in the restricted space available in the nose of Luftwaffe fighters, originally designed to house the lighter-caliber 7.92mm machine guns. This became the common configuration from 1943 onwards, as the increasing armour protection of most Allied aircraft and the increasing challenge of daylight raids by heavy American bombers as the war progressed rendered the smaller-caliber guns obsolescent in this role.

Lower ballistic properties that were still adequate for the task were obviously seen as an advantage: the gun was very accurate (35 × 45 cm spread at 100 m), and the barrel wore out much less quickly (barrel life of the MG 131 was 17,000 rounds), which meant that ballistic properties deteriorated more slowly.

It was installed in the Messerschmitt Bf 109, Me 410 Hornisse, Fw 190, Ju 88, Junkers Ju 388, He 177 Greif bomber variants, and many other aircraft. The Fernbedienbare Drehlafette FDL 131Z remotely controlled gun turret system used either a single or, more commonly, a pair of MG 131s for dorsal defense. The quadmount Hecklafette HL 131V weapons "system" for tail defense, had two MG 131 guns apiece in a pair of rotating, side-mount exterior elevation carriages (the manned turret "core" provided the traverse function), was meant for standardization on many late-war prototype developments of German heavy bomber airframes, but never came to fruition beyond a small number of dimensional prototype mockups and kinetic test units.

The MG 131 fired electrically primed ammunition in order to sustain a high rate of fire when shooting through the propeller disc of a single-engined fighter. A pair of MG 131 machine guns was used as cowl armament on later models of the Bf 109G and the Fw 190.

A variant for use on the ground, sometimes referred to as the "MG 131E" or "MG 131E-1," was trialed, with little information known. It was not utilized operationally nor placed into production. The weapon could be utilized with a shoulder stock and bipod and its electric firing system was maintained via a battery.

Technical data

13 mm MG 131 and 20 mm MG 151/20 ammunition
  • Weight: 16.6 kilograms (37lb)
  • Length: 1,185mm (3.888ft)
  • Muzzle velocity: 750m/s (2,500ft/s)
  • Rate of fire: 900 rpm AP-API; 930 rpm HEF-HEFI-I
  • Accuracy: 35 × 45 cm spread at 100 m
  • Barrel life: 17,000 rounds

Ammunition specifications

The MG 131 is the sole user of the electrically primed 13×64 mm B cartridge. A mechanically primed variant was produced in small quantities in Spain for unknown uses.

German designationUS abbreviationProjectile weight [g]Bursting charge [g]Muzzle velocity [m/s]Description
13 mm Sprenggranatpatrone L'spur El. mit/ohne ZerlegerHEF-T34±11.2–1.4g HE (PETN) + (blasting cap): 0.2g HE (PETN) + 0.4g HE (lead azide)-(tetrazene explosive)750Nose fuze, tracer, with or without self-destruct
13 mm Brandsprenggranatpatrone L'spur/Gl'spur El. ohne ZerlegerHEFI-T34±10.9g HE (PETN) + (blasting cap): 0.2g HE (PETN) + 0.4g HE (lead azide)-(tetrazene explosive) + 0.3g incendiary (elektron) (thermite)750Nose fuze, tracer, no self-destruct
13 mm Brandgranatpatrone El. ohne ZerlegerI32±1?g incendiary (BaNO3+Al+Mg)770Nose fuze, no tracer, no self-destruct On impact, the priming charge shears away the grenade's cardboard head and sheet metal cap and ignites the incendiary charge in the projectile, which is sprayed forward up to 5 m of projectile travel. In air combat as a carrier of the incendiary effect, especially for the incendiary shooting of fuel tanks. As an indestructible body, it remains effective even after penetrating several bulkheads.
13 mm Brandgranatpatrone L'spur/Gl'spur El. ohne ZerlegerI-T34±1?g incendiary (BaNO3+Al+Mg)770Nose fuze, tracer, no self-destruct On impact, the priming charge shears away the grenade's cardboard head and sheet metal cap and ignites the incendiary charge in the projectile, which is sprayed forward up to 5 m of projectile travel. In air combat as a carrier of the incendiary effect, especially for the incendiary shooting of fuel tanks. As an indestructible body, it remains effective even after penetrating several bulkheads.
13 mm Panzergranatpatrone L'spur/Gl'spur El. ohne ZerlegerAP-T38.5±1none (bakelite filling in cavity)710No fuze, tracer, no self-destruct. Penetration 10-14-17mm of armour at 60-75-90-degree impact, 100 m range
13 mm Panzerbrandgranatpatrone (Phosphor) El. ohne ZerlegerAPI38±10.36g incendiary (WP)710No fuze, no tracer, no self-destruct. Penetration 10-14-17mm of armour at 60-75-90-degree impact, 100 m range Incendiary effect also against protected fuel tanks when the specially hardened tail section of the grenade and the incendiary capsule break. The range of the incendiary effect extends over a distance of 2 m after the incendiary charge is released.

See also

External links

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