Also known as Ma Deuce.
.50 calibre (12.7mm) heavy machinegun, designed by Browning, and the oldest weapon system still in general use in the US Military. Has achieved considerable export success.
Derived from an anti-tank rifle, turned into a machinegun, the basic design dates from the 1920s. The ubiquitous weapon could be found on anything from WWII era fighter aircraft through the latest M1A2SEP Abrams tanks. With an ROF of 550RPM and 100 round belts, the system was used as an anti-air, anti-personnel, and anti-armour weapon. Contrary to urban myth, there is no legal prohibition on the use of .50 cal against troops.
Later versions of the weapon come with a quick-change barrel, with no requirement to check headspace and timing. Almost all current service M2s in US service are of the older configuration. The M2 as found on the M1A1 and some earlier tanks is slightly modified to fit the mounting, and has a safety switch vice the rotating semi/auto selector on the normal M2, and has a charger cable on the left instead of the charging handle on the right. This configuration is known as the M2 with M10 Charger for M48 Chrysler Mount.
Current service rounds are ball, SLAP (Saboted Light Armour Piercing), tracer, API (Armour Piercing Incendiary)