The M134 Minigun is an externally operated weapon which uses electrical motor drive to operate its action. The gun operates on Gatling principle, that is it employs a rotary cluster of six barrels, each with its own bolt group. Bolts are moved back and forth behind each barrel as their operating roller passes an internal curved track machined inside the receiver cover. Typically, the topmost barrel in the cluster has its bolt fully open and the bottom barrel in cluster has its bolt fully closed, locked and firing pin released to fire the loaded cartridge. Barrel locking is achieved by the rotary bolt head. Since the gun operates on external power, it is immune to dud / misfired rounds, which are ejected during the normal cycle of operation. Feed is provided either by linkless chute or by the linked ammunition, In the latter case, a powered feeder/delinker module is installed on the gun; it receives necessary power through the gear from the gun motor. To properly operate the gun, it is fitted with electronics control box, which, in the case of manually controlled installation, has an 'master arm' switch and fire controls (triggers).
Designed in SolidWorks 2012, rendered in KeyShot 4.