The PWS MK114 Mod 2-M complete upper (PWS part no. MK1M2U6ARC14) brings the PWS long-stroke piston system to the 6mm ARC cartridge on a 14.5-inch barrel, giving a compact build the same low-fouling, suppressor-optimized gas system PWS is known for.

Key Specifications

• Brand: PWS.
• Caliber: 6mm ARC.
• Model line: MK114 Mod 2-M.
• Gas system: PWS long-stroke piston.
• Handguard: free-float M-LOK.

Frequently Asked Questions

Is a 14.5in complete upper legal to buy without a lower? Yes. A complete upper with no lower receiver is a Title I part, not itself the regulated firearm. Mounting it on an already-stocked, non-NFA-registered lower would create an unregistered short-barreled rifle, so pair it with a pistol lower/brace or a Form 1-approved SBR lower.

What gas system does this upper use? The PWS long-stroke piston system, which runs cleaner and cooler than a direct-impingement gas tube.

Buy the PWS MK114 Mod 2-M Complete Upper, 6mm ARC, 14.5in

Get the PWS MK114 Mod 2-M Complete Upper, 6mm ARC, 14.5in from PWS, browsable in our full AR15 Uppers selection. Our Lubbock, Texas team ships fast, insured orders every day.