Primary Weapons Systems 6mm ARC AR Rifle

Description

The PWS MK118 MOD 2-M is built for precision hunters and long-range target shooters who want to run 6mm ARC in a platform that stays cleaner and cooler under sustained fire than a direct-impingement design. The long-stroke piston system moves the operating energy forward and away from the bolt carrier group, which means less heat and carbon fouling accumulating in the receiver — a practical advantage during extended range sessions or when running a suppressor.

The 18-inch barrel is where the 6mm ARC cartridge earns its keep. The round was engineered to extract long-range ballistic performance from the AR-15 format — high ballistic coefficients, flat trajectories, and retained terminal energy at distance that shorter barrel lengths can’t fully realize. The 1:7.5-inch twist rate stabilizes the heavier, high-BC projectiles that make 6mm ARC worth shooting in the first place; lighter or shorter bullets will also stabilize at that rate, so ammunition selection across the current 6mm ARC catalog is largely unrestricted. The barrel is manufactured at PWS’s Boise, Idaho facility from 41V50 chrome moly vanadium steel and carries a sub-MOA accuracy guarantee with quality ammunition.

The three-position adjustable gas block lets the shooter tune dwell time without tools — one setting for standard use, a reduced setting when running a suppressor, and a third for ammunition that runs on the lighter side of the pressure curve. The ambidextrous lower is machined from 7075-T651 forged aluminum with a flared magwell, integrated trigger guard, and no forward assist. The PicLok handguard combines M-LOK attachment points with integrated Picatinny rail sections. A Radian Raptor charging handle, Magpul MOE SL stock, MOE K2 grip, and a 5/8×24-threaded muzzle device round out the package. The rifle ships with one 15-round magazine.