USMC May Buy Up To 2.4 Million Rounds of Polymer-Cased .50 Calibre Ammunition

    M2 Browning

    A U.S. Marine with II Marine Expeditionary Force Information Group, fires an M2 machine gun during the II MIG Field Exercise at Camp Lejeune, N.C., March 5, 2018. (U.S. Marine Corps photo by Pfc. Larisa Chavez)

    An intent to sole source solicitation notifying of the potential order of an estimated 2.4 million rounds of polymer-cased .50 calibre ammunition has been posted, advising that MAC, LLC of Bay St. Louis, Mississippi may in the future receive an order for ammunition. The notice follows the USMC’s earlier survey of manufactures to find a suitable provider for the new ammunition. The Marine Corps Systems Command notes that future orders may include both ball and API ammunition.

    MAC, LLC recently became part of the Norwegian defence company Nammo, known for their development of ammunition. According to their old website, MAC had previously focused on “development and commercialization of lightweight, polymer-based solutions.” In January, Nammo announced that they had taken majority ownership of MAC, with Reijo Bragberg, Executive Vice President of Nammo Small and Medium Caliber Ammuniton, saying:

    Through this decision we are now establishing Nammo and MAC LLC as frontrunners in development of lightweight technologies, which are of great importance for our defense customers.

    The Marine Corps has been interested in polymer-cased .50 calibre ammunition for a number of years. Back in 2017, William Williford, executive director of Marine Corp Systems Command, said: “We have to have lighter equipment… On a .50-caliber pallet, we think we can save 1,000 pounds per pallet.”

    In April 2018, the USMC issued a Request for Information (RFI) to find interested industry partners for the production of “Lightweight .50 Caliber Ammunition which will provide weight savings when compared to the current M33 .50 cartridge in the DODIC A555 linked configuration.” It appears that MAC LLC have fulfilled the earlier RFI.

    Here’s the intent to sole source in full:

    Marine Corps Systems Command (MCSC) intends to award a sole-source contract to MAC, LLC of Bay Saint Louis, MS.  The requirement is for polymer-cased .50 caliber machine gun ammunition and includes an anticipated total estimated quantity of 2.4M cartridges over a three year ordering period.  Requirement is anticipated to include both ball and API ammunition. Cartridges are subject to Weapons Systems Explosives Safety Review Board (WSESRB) qualification and certification.

    Here’s a 2016 video from MAC showing production of lightweight polymer-cased ammunition:

    The intent to sole source represents the USMC’s next step towards what may be one of the first major orders for polymer-cased ammunition by the US military. Polymer-cased ammunition will also likely play an important role in the Army’s Next Generation Squad Weapons programme. While the touted 30% weight savings of polymer-cased ammunition will, in theory, lighten the average Marine’s load, there are some concerns about the environmental impacts of polymer ammunition which have yet to be fully addressed.


    This article has been updated to clarify the nature of an ‘intent to sole source’ notice.

    Matthew Moss

    _________________________________________________________________________ – Managing Editor – Managing Editor

    Matt is a British historian specialising in small arms development and military history. He has written several books and for a variety of publications in both the US and UK. He also runs Historical Firearms, a blog that explores the history, development and use of firearms. Matt is also co-founder of The Armourer’s Bench, a video series on historically significant small arms.

    Here on TFB he covers product and current military small arms news.

    Reach Matt at: [email protected]