Attached is an article about the Browning ANM2 .30 caliber aircraft machine gun used during WWII. It was also adapted for ground use by the Marines in the Pacific because of it's very high rate of fire:
https://www.americanrifleman.org/ar...wsletter&utm_medium=insider&utm_campaign=0516
https://www.americanrifleman.org/ar...wsletter&utm_medium=insider&utm_campaign=0516