PWS MK114 MOD 2-M UPPER 223 WYLDE 14.5

The PWS MK114 MOD 2-M upper receiver in .223 Wylde is a complete piston-driven upper built for shooters who demand reliability and flexibility in a mid-length platform. Primary Weapons Systems engineered this upper around their proven long-stroke piston system, which runs cleaner and cooler than direct impingement while maintaining the ergonomics and controls you expect. At 14.5 inches, the barrel strikes a practical balance between velocity and handling in configurations where you need a compact footprint without sacrificing performance. Whether you're building a duty rifle, a do-everything patrol gun, or a versatile hunting upper, the MK114 MOD 2-M delivers the accuracy and dependability that PWS is known for.

The heart of this upper is PWS's proprietary piston system with a 3-setting adjustable gas block, letting you tune the gun to your specific ammo, suppressor setup, or operating conditions. The barrel—cut at a 1:8 twist—stabilizes a wide range of .223 Wylde loads and delivers a muzzle velocity of 2921 fps. The upper receiver itself is machined from 7075-T651 aluminum and hard-coat anodized per Mil-Spec 8625 Type III, Class 2, so it'll handle hard use without compromise.

The 13.574-inch PicLok handguard provides plenty of real estate for optics, lights, and accessories while staying true to PWS's integrated design philosophy. Charging is handled by a Radian Raptor ambidextrous charging handle, meaning left-handed and right-handed shooters both get a smooth, reliable pull. Note that muzzle device availability varies—the upper may ship with a PWS FSC 556 pinned and welded, or without a device, depending on your order configuration. Either way, you're starting with a battle-tested upper ready to accept your lower and go to work.

Key Features

• PWS long-stroke piston operating system with 3-setting adjustable gas block for tuning and reliability
• 14.5-inch barrel in .223 Wylde, 1:8 twist for broad ammunition compatibility
• Proprietary PWS upper receiver, 7075-T651 aluminum with Mil-Spec hard-coat anodize
• 13.574-inch PicLok integrated handguard with ergonomic geometry
• Radian Raptor ambidextrous charging handle for shooter preference and ease of use
• Mid-length gas system for balanced recoil impulse and reliability

Specifications

Frequently Asked Questions

What lower receiver does the MK114 MOD 2-M upper pair with?

This is a complete upper receiver assembly. It is compatible with standard AR-pattern lower receivers. You'll need to source and assemble a lower separately to create a complete rifle.

Is this upper legal to own in all 50 states?

The MK114 MOD 2-M is offered with or without a muzzle device depending on configuration. If your configuration includes the pinned and welded FSC 556, the barrel is permanently locked at 14.5 inches. All NFA rules apply. Check your local and state regulations before ordering, as barrel length, muzzle device, and other features are restricted in some jurisdictions.

What's included in the box?

The complete upper assembly includes the upper receiver, barrel, piston system with adjustable gas block, PicLok handguard, charging handle, and either a pinned/welded muzzle device or nothing, depending on your specific configuration. Lower receiver, bolt carrier group, and lower parts are not included.

Can I adjust the gas system on the fly?

Yes. The PWS long-stroke piston system features a 3-setting adjustable gas block, allowing you to tune the rifle's gas flow for different ammunition types, suppressed fire, or operating conditions without tools.