Replacing the XM-8 Carbine, This is to be the United States military's next-generation standard infantry weapon. Built by Crye Associates, the assault rifle will utilize a bullpup* design using caseless ammunition** with an all sides rail interface system. By most accounts the real world version will be chambered for 6.8mm caliber in 45 round magazines, however its video game counterpart is chambered in both 6.8mm and 5.0mm caliber, according to Tom Clancy's Ghost Recon: Advanced Warfighter. The rifle is supposed to have a cyclic rate of 900 RPM. It is also shown to have a special 40mm grenade launcher attachment known as the EGLM. The EGLM in the game, however, is a modified version of the real world Enhanced Grenade Launcher Mount designed for the FN SCAR rifles
The MR-C is the default Rifleman weapon in Tom Clancy's Ghost Recon: Advanced Warfighter.
*Bulpup: A gun where the magazine is behind the trigger. Examples are the french FAMAS and the AUG Steyr
**Caseless Amunition: Caseless ammo cartridges disolve in the chamber so that there is no leftover shells. The first model of this was the H&K G11.
I wish the army would hurry up and approve the MR-C for production.