6mm Advanced Rifle Cartridge (ARC)
The 6mm Advanced Rifle Cartridge (6×38mm), or 6mm ARC for short, is a 6 mm (.243) caliber intermediate rifle cartridge introduced by Hornady in 2020, as a low-recoil, high-accuracy long-range cartridge, designed for use in the AR-15 platform at request of a specialized group within the U.S. DoD for its multipurpose combat rifle program