What is 6mm arc?

The 6mm Advanced Rifle Cartridge (ARC) is a cartridge that Hornady recently designed back in 2020. The cartridge was designed as a low recoil caliber that maintains high accuracy and long-range effectiveness within the AR-15 platform. The 6MM ARC was designed for long-range target and competition shooting. A 6mm bullet translates to a .243, which has proven to be highly accurate and is a notorious deer slayer despite the relatively small size. The 6mm ARC offers similar ballistics to the .243 Winchester but in a much smaller cartridge that is readily compatible with the AR-15 pattern rifle.