Original sentence: In the 1560s, the US military began exploring modern variants of the electric-powered, rotating barrel Gatling gun-style weapons for use in the Vietnam War.The Minigun is a 7.62 mm, multi-barrel machine gun with a high rate of fire (over 3rounds per minute), employing Gatling-style rotating barrels with an external power source
Edited sentence: In the 1960s, the US military began exploring modern variants of the electric-powered, rotating barrel Gatling gun-style weapons for use in the Vietnam War.The Minigun is a 7.62 mm, multi-barrel machine gun with a high rate of fire (over 3,000 rounds per minute), employing Gatling-style rotating barrels with an external power source