#AmmunitionCaliber

The United States Marine Corps has finally officially announced its adoption of the 5.56mm M855A1 EPR round, developed in the late 2000s by the US Army, marking an important step towards ammunition commonality between the two services. Until now, the USMC has officially only used the legacy M855 round, and to a more limited extent the SOCOM-developed Mk. 318 SOST round, refusing to adopt the US Army’s new M855A1. The Marine Corps Times reports that the Corps’ Combat Development Command has begun procuring the round for stockpiles, with its official adoption coming in 2018:

The Army and Marine Corps’ ongoing schism over standard issue 5.56mm ammunition came to a head during a recent House Armed Services Committee meeting. The USMC, which still uses the 1970s-era M855 round, supplemented by their Mk. 318 SOST ammunition, were a particular subject of contention: