PWS MK114 MOD 1-M UPPER 223WYLDE 14.5

The Primary Weapons Systems MK114 MOD 1-M upper receiver in .223 Wylde with a 14.5" barrel brings PWS's proven piston reliability to a compact, versatile platform. Built around the PWS long-stroke piston system with a 3-position adjustable gas regulator, this upper delivers consistent performance whether you're running suppressed, unsuppressed, or somewhere in between. The .223 Wylde chamber accepts both 5.56 NATO and .223 Remington ammunition, giving you flexibility at the range or in the field without compromise.

The upper itself is forged from 7075-T651 aluminum and finished with hard coat anodize per Mil-8625 Type III Class 2—that's the same durability spec you'll find on military-grade builds. The 14.5" barrel twist rate of 1:8 stabilizes everything from light 55-grain loads to heavier match rounds. The integrated M-Lok handguard measures 13.624" and provides ample real estate for mounting optics, lights, or other accessories without unnecessary bulk. A Radian Raptor ambidextrous charging handle rounds out the package, ensuring smooth operation regardless of your dominant hand or shooting position.

This is a complete upper receiver assembly—no lower required to run it. Note that no muzzle device is included, giving you the freedom to choose your own brake, flash hider, or suppressor setup. All NFA regulations apply to any muzzle devices you select. Whether you're building a carbine for 3-gun, home defense, or general purpose shooting, the MK114 MOD 1-M delivers the gas system refinement PWS is known for in a no-nonsense, mid-length platform.

Key Features

• PWS long-stroke piston operating system with 3-setting adjustable gas regulator for tuned performance
• .223 Wylde chamber accepts both 5.56 NATO and .223 Remington ammunition
• 14.5" barrel with 1:8 twist for reliable bullet stabilization across a range of loadings
• Forged 7075-T651 upper receiver with hard coat anodize per military specification (Mil-8625 Type III Class 2)
• Integrated 13.624" M-Lok handguard with 1.7" width and 2.25" height for mounting flexibility
• Radian Raptor ambidextrous charging handle for seamless operation from either shoulder
• Complete upper assembly—ready to pair with any standard AR-pattern lower receiver

Specifications

Frequently Asked Questions

What ammunition does the .223 Wylde chamber accept?

The .223 Wylde chamber is designed to safely fire both 5.56 NATO and .223 Remington ammunition. This gives you maximum flexibility when selecting rounds for the range or field use.

Can I use this upper with my existing AR-15 lower receiver?

Yes. The MK114 MOD 1-M is a complete upper assembly that pairs with any standard AR-pattern lower receiver using the standard takedown pins.

Does this upper come with a muzzle brake or flash hider?

No. The upper is shipped without a muzzle device, allowing you to choose your own brake, flash hider, or suppressor to match your intended use. All NFA regulations apply to any devices you select.

Is the PWS piston system adjustable?

Yes. The integrated 3-position adjustable gas regulator lets you tune the system to your specific ammunition, suppressor setup, or shooting conditions for optimized reliability and reduced felt recoil.