STAYING SHARP: Marines from the 31st Marine Expeditionary Unit (MEU) fire a .50-caliber machine gun during a crew served weapons shoot aboard dock landing ship USS Germantown. This second photo (from 2009) shows sailors in a fifty caliber live fire exercise. Here is an excellent background article from 2015 on the Ma Deuce (the fifty cal’s nickname). “The M2 has lasted so long because it proved to be the most reliable and durable machine-gun of any caliber ever produced.” Finally, here’s a recent article on a possible Ma Deuce successor. We’ve heard that before. The fifty cal is the tank commander’s weapon. My old M60A1 had the M85 version of the Ma Deuce.