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 (which originally required one blister or Beule on each side of the fuselage, flanking the upper rear end of the engine, to house the larger breech of the new gun) and the Fw 190. Technical data Weight : Length : Muzzle velocity : ~ Rate of fire : 900 rpm AP-API ; 930 rpm HEF-HEFI-I Acccuracy : 35 x 45 cm spread at 100 m Barrel Life : 17,000 rounds Ammunition specifications The MG 131 is the sole user of the electrically-primed 13×64mm B cartridge. A mechanically-primed variant was produced in small quantities in Spain for unknown uses. See also List of common World War II infantry weapons List of firearms M2 Browning machine gun References External links Municion.org query for 13 x 64 ammunition (for more types with images and markings) Image http://www.lexikon-der-wehrmacht.de/Waffen/Bilderseiten/bordwaffen-R.htm https://web.archive.org/web/20071130005600/http://library.thinkquest.org/C006001/armament/mg131.html https://web.archive.org/web/20091027135418/http://geocities.com/Augusta/8172/panzerfaust5.htm Aircraft guns Heavy machine guns Machine guns of Germany World War II machine guns Rheinmetall Weapons and ammunition introduced in 1940