Remington's 6.8x43 mm SPC: History & Performance | An Official Journal Of The NRA
Developed at the request of U.S. Special Forces, the new M468 6.8x43 mm Special Purpose Cartridge and Barrett’s Special Purpose Carbine address many of the perceived shortcomings of the 5.56x45 mm cartridge. Fielded in limited numbers by the U.S. military, does the future lie with the 6.8?
Source: americanrifleman.org