The steel M2A1 Ammunition Can / Box (also called Chest Ammunition: M2A1 or Box, Metal, M2A1) was introduced during the 1950s for .50 caliber machine gun ammunition, replacing the M2 .50 cal. ammunition can / box. The M2A1 ammo can was designed to hold link belts of 100 cartridges of .50 cal. ammunition for the M2 Browning machine gun, but was in fact utilized to transport and store many other ammo calibers and packaging.
The .30 caliber M19 / M19A1 steel ammunition can / box was developed to deliver belts of 250 .30-06 cartridges for the .30 Cal. Browning machine guns and was later used for the NATO equivalent 7.62mm rounds for the M60 machine gun and other weapons. It has also been used for various calibers in cartons, clips, bandoleers or other packaging. The .30 cal. steel M19 / M19A1 ammo can replaced the steel Cal .30 M1 / M1A1 ammunition box after World War II.
The newer M2A2 ammo can is identical to the M2A1 with one important exception: the M2A2 features an additional metal support bracket in its latch assembly. The bracket prevents the M2A2's rubber gasket from getting crushed while it is under pressure (i.e. when multiple full cans are stacked on top of one another for extended periods of time). As such, the M2A2 protects its contents with a more reliable watertight seal.
