The Primary Weapons Systems Mk114 Mod 1-M upper receiver in 6 ARC pairs a 14.5-inch lightweight barrel with Primary Weapons' Force Compensator to deliver a complete, ready-to-assemble upper for shooters building or upgrading an AR platform rifle. The 6 ARC cartridge has earned a following among precision rifle hunters and match competitors for its efficiency at distance: it delivers magnum-level performance in an intermediate case, which means less recoil, faster follow-up shots, and less ammunition consumption compared to larger magnums. Pair this upper with your lower receiver and bolt carrier group, and you've got a modern, compact rifle suitable for hunting medium game or running precision drills on the range.

The 14.5-inch barrel gives you a balance of velocity and handling. You lose some of the speed you'd get from a 20-inch match barrel, but you gain real-world portability—crucial if you're glassing hillsides, navigating thick timber, or setting up for a long day in the field. The lightweight profile keeps the rifle nimble without sacrificing stiffness where it matters.

Primary Weapons Systems builds their uppers to tight tolerances and test-fires them before they leave the shop. The Force Compensator manages recoil and can help with muzzle rise, which supports faster, more accurate follow-up shots. This is a no-nonsense upper from a builder with a strong reputation in the AR market—built for hunters and shooters who want to spend less time worrying about reliability and more time shooting.

The Primary Weapons Systems Mk114 Mod 1-M upper receiver in 6 ARC pairs a 14.5-inch lightweight barrel with Primary Weapons' Force Compensator to deliver a complete, ready-to-assemble upper for shooters building or upgrading an AR platform rifle. The 6 ARC cartridge has earned a following among precision rifle hunters and match competitors for its efficiency at distance: it delivers magnum-level performance in an intermediate case, which means less recoil, faster follow-up shots, and less ammunition consumption compared to larger magnums. Pair this upper with your lower receiver and bolt carrier group, and you've got a modern, compact rifle suitable for hunting medium game or running precision drills on the range.

The 14.5-inch barrel gives you a balance of velocity and handling. You lose some of the speed you'd get from a 20-inch match barrel, but you gain real-world portability—crucial if you're glassing hillsides, navigating thick timber, or setting up for a long day in the field. The lightweight profile keeps the rifle nimble without sacrificing stiffness where it matters.

Primary Weapons Systems builds their uppers to tight tolerances and test-fires them before they leave the shop. The Force Compensator manages recoil and can help with muzzle rise, which supports faster, more accurate follow-up shots. This is a no-nonsense upper from a builder with a strong reputation in the AR market—built for hunters and shooters who want to spend less time worrying about reliability and more time shooting.