The XM556 Microgun was designed and engineered around the 5.56mm NATO cartridge. This defensive suppression weapon is significantly smaller and lighter than its big brother the M134. It was meant to stand in place of anywhere high suppressive fire wanted without the weight or footprint of the larger M134 electrically driven Gatling gun system. The current XM556 Microgun is smaller and lighter than some current 5.56mm belt-fed Squad Automatic Weapons currently on the market, with 4x’s the firepower.