M3 Aircraft 50BMG Machine Gun: The Ventilator During World War II, a faster-firing Browning was developed for aircraft use. The AN/M3 features a mechanical or electrically boosted feed mechanism to increase the rate of fire to around 1,200 rounds per minute. More info on Wikipedia at http://en.wikipedia.org/wiki/M2_Browning#AN.2FM3.2C_GAU-21.2FA.2C_and_M3P