XM214 Microgun The XM214 is a prototype 5 . 56 mm rotary - barreled machine gun . It was designed and built by General Electric , but it never reached mass production . Also known as the Microgun , the XM214 was a scaled - down version of the M134 " minigun " , firing M193 5 . 56 x 45 mm ammunition . Development . The XM214 was first developed for aircraft applications . Later General Electric developed it into a man - portable weapon system , known as the GE Six - Pak . The complete Six - Pak system weighed 85 pounds ( 38 . 5 kg ) with 1 , 000 rounds of ammunition , comparable in weight to some heavy machine guns . The basic gun in the Six - Pak weighed 27 pounds , or 12 . 2 kg . The system could be carried by a team of two soldiers and mounted either to an M122 tripod or a vehicle ' s pintle mount . Length overall is 104 . 1 cm , gun only is 68 . 6 cm long . Width ( including ammunition case ) is 44 . 4 cm . Sighting was usually by optical telescope . The Six - Pak consisted of the XM214 , the ammunition package , and the power module , and the ammunition module consisted of two 500 - round , factory packed , and disposable cassettes mounted to a holding rack . Linked ammunition was fed through a flexible chute to the gun ; when the first cassette was empty , ammunition would then feed from the second cassette , tripping a visible signal that a new cassette needed to be added to the rack . The power module contained a 24 - volt nickel - cadmium battery , a motor , and solid state electronic controls . Unless the battery was plugged into a vehicle ' s power supply , the battery ' s charge would be depleted after 3 , 000 rounds . The system could be broken down quickly into two portable loads of roughly 42 pounds apiece . This was accomplished by means of a quick - release fitting at that end of the belt chute fastened to the gun . Electronic controls contained a burst limiter and handled the automatic clearing of the gun after bursts . Using the electronic controls , the weapon ' s rate of fire could be adjusted from 400 rpm all the way up to 4 , 000 rpm . Later editions of " Jane ' s Infantry Weapons " claimed a theoretical cyclic rate of up to 6 , 000 rpm . George Chinn , author of " The Machine Gun Volume V " , contended that the XM214 prototype had a rate of fire of up to 10 , 000 rpm , but the man - portable Six - Pak was limited to 4 , 000 rpm . Microgun Pod . An 88 by 10 inch ( 224 x 25 cm ) 5 . 56mm Microgun Pod was also developed for external use on light aircraft and helicopters . The unit had an ammunition capacity of from 1 , 500 to 3 , 500 rounds and loaded weight of 186 to 300 pounds . The feed system was linkless , via a helical drum , with a nominal rate of fire of 6 , 000 rpm . However , adjustments to 1 , 000 or 10 , 000 rpm were possible , if desired . Power could be provided by a built - in battery pack , or from the aircraft itself . Possible resurrection . The rise of MOUT tactics in the early 2000s led to the possible resurrection of the XM214 system in a tank / APC CIWS role . General Dynamics , who held the license for the Microgun , increased the rate of fire to 12 , 000 rpm and offered the weapon mounted on armored fighting vehicles as anti - RPG or anti - ATGM defense . As of c . 2011 , the XM214 has been dropped from the General Dynamics catalogue and replaced by the Iron Fist Active Protective System ( APS ) .