is a heavy machine gun that was designed near the end of World War I. While similar to Browning's M1919 Browning machine gun, which was chambered for the .30-06 cartridge, the M2 uses Browning's larger and more powerful .50 BMG (12.7 mm) cartridge. The design has had many designations.
The AN/M2 aircraft gun has a cyclic rate of 750–850 rpm . The M2 has an effective range of 1,830 metres (2,000 yd) and a maximum effective range of 2,000 metres (2,200 yd) when fired from the M3 tripod. In its ground-portable, crew-served role as the M2HB, the gun itself weighs 84 pounds (38 kg) and the assembled M3 tripod another 44 pounds (20 kg).