The Primary Weapons Systems MK114 Mod 1-M Complete Long Stroke Piston Upper Receiver in Black is built around PWS’s proven long stroke gas piston system for smooth, reliable operation. This assembled upper features a 14.5 inch barrel capped with an FRC 3-port compensator and a slim, full-length M-LOK handguard, giving shooters a refined, controllable platform ready to mount on a compatible AR-15 lower.
This upper is well suited for range use, training, and hunting where the efficient 6mm ARC cartridge and flat trajectory can shine. The 3-setting adjustable gas system allows tuning for different loads or suppressed shooting, while the extended Picatinny rail provides ample space for optics and accessories. Built with the attention to detail Primary Weapons Systems is known for, this upper offers a balance of reliability, control, and modern ergonomics.
- Manufacturer: Primary Weapons Systems
- Model: MK114 Mod 1-M Upper 6mm ARC 14.5 LS FRC Comp
- Barrel Length: 14.5 Inches
- Gas System: Long Stroke Piston With 3-Setting Adjustable Gas
- Muzzle Device: FRC 3-Port Compensator
- Handguard: Slim Full-Length M-LOK With Continuous Top Picatinny Rail
- Configuration: Complete Upper Receiver
| __Firearm Type | Rifle |
| __Caliber | 6mm ARC |
| __Model | MK114 Mod 1-M |
| __Capacity | NA |
| __Barrel Length | NA |
| __Optic Footprint | NA |
| __Action | NA |
