For the majority of the Vietnam War , the principal weapon of the door gunner was a medium machine gun ( MG ) , initially , a M1919A4 . 30 caliber MG .
Soon thereafter , the M60 7.62 mm MG became the standard helicopter door armament system .
For the majority of the Vietnam War , the principal weapon of the door gunner was a medium machine gun ( MG ) , initially , a M1919A4 . 30 caliber MG , and soon thereafter , the M60 7.62 mm MG became the standard helicopter door armament system .