The U.S. Marine Corps is looking for .50 caliber ammunition that is 30 percent lighter than the linked belts it is currently using.

Lightweight .50 Caliber Ammunition

According to, Marine Corps Systems Command has issued a RFI to gauge industry’s “interest and capabilities” for producing .50 caliber ammunition that weighs less than the “M33 .50 cartridge in the DODIC A555 linked configuration.”

“A belt of 100 Lightweight .50 Caliber cartridges with 101 links shall have a threshold overall weight of 24.6 lbs. or 15% weight savings compared to the legacy A555 configuration (T),” the RFI says. “A belt of 100 lightweight cartridges with 101 links shall have an objective overall weight savings of more than 20.3 lbs. or 30% compared to the legacy A555 configuration (O).”

The technical requirements also say the overall length of the new, lightweight .50 caliber ammunition should be 5.45 inches. In addition, the cartridge’s action time (overall primer ignition; propellant burning; time taken for the bullet to exit the barrel) when conditioned and functioned at around 70 degrees fahrenheit should be no more than four milliseconds. Meanwhile, the average velocity of the 30 sample cartridges “shall be 2,905 feet per second (fps) ± 30 fps at 78 feet from the muzzle of the weapon. The standard deviation of the velocity shall not exceed 36 fps.”

Marine Corps Systems Command says the new cartridge should reliably function in the M2HB machine gun; M2A1 machine gun; GAU-19 gatling gun; GAU-21 aircraft machine gun; and a M107 sniper rifle.

Interested parties have until June 1, 2018 to submit responses. To read the RFI and the requirements in full, visit

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