The Primary Weapons Systems MK118 Mod 1-M Complete Upper Receiver in 6mm ARC brings a refined, piston-driven upgrade to the AR-15 platform. Built around an 18-inch threaded barrel and PWS’s proven long stroke piston system, this upper is engineered to run cleaner with reduced fouling while maintaining consistent accuracy and smooth cycling. The forged 7075-T651 aluminum receiver and free-float M-LOK handguard create a rigid, well-balanced assembly ready for precision-focused shooting.
Chambered in 6mm ARC, this MK118 Mod 1-M upper offers flat trajectories, excellent retained energy, and mild recoil that suits extended range sessions, varmint hunting, and precision training. The adjustable gas system allows tuning for different loads and suppressor use, while the included Radian Raptor ambidextrous charging handle enhances usability for right- and left-handed shooters. For shooters seeking a dependable, accuracy-driven upper that integrates seamlessly with standard AR-15 lowers, Primary Weapons Systems delivers a thoughtfully executed solution backed by their reputation for innovative piston designs and meticulous craftsmanship.
- Manufacturer: Primary Weapons Systems
- Model: MK118 Mod 1-M Upper
- Caliber: 6mm ARC
- Barrel Length: 18 in
- Product Type: AR Uppers
- Color: Black
- Gas System: PWS Long Stroke Piston, Adjustable
| __Firearm Type | Rifle |
| __Material | 7075-T651 Aluminum, Steel |
| __Caliber | 6mm ARC |
| __Capacity | NA |
| __Barrel Length | NA |
| __Optic Footprint | NA |
| __Action | NA |
| __Model | MK118 Mod 1-M |
