Mk 14 Mod 0 EBR with a Harris bipod and RIS foregrip - 7.62x51mm NATO. This weapon is actually called Mark 14 Enhanced Battle Rifle. Even though the internal parts are from an M14, this weapon is only called M14 EBR in US Army service. This is a common mistake. It was developed for the US Navy SEALs, and thus it is type classified as a "Mark" weapons system by them.