Picture of the M2 in Real Life
The Browning M2 is .50 cal heavy machinegun, which was air-cooled, belt-fed and recoil operated. It was used designed after World War 1 and was mounted on aircraft and vehicles, it had an effective range of 2200yards.
 Call of Duty
The Browning M2 was used a few times in Call of Duty 3 mainly when your'e attacking the fuel plant with a vehicle convoy or when advancing through villages to find the French Resistance soldiers taken hostage.