PWS MK2 MOD 2 Uppers: Modular .308 Piston Power
Following the release of Primary Weapons Systems’ MK2 MOD 2-M earlier this summer, PWS is now giving large-frame AR owners and enthusiasts a simple way to upgrade to the company’s renowned long-stroke piston operating system without needing to purchase a complete rifle.
These complete MK2 MOD 2 upper assemblies are available in 16.1-inch and 18-inch .308 Win. configurations. Designed to pair seamlessly with compatible existing lower receivers, these complete uppers provide a suppressor-ready, out-of-the-box solution that delivers the reliability, cleaner operation, and sub-MOA accuracy that define the PWS platform.
Built around a 416R stainless steel barrel chambered in .308 Winchester with a 1:10 twist rate, MK2 MOD 2 uppers are engineered to stabilize a broad range of bullet weights while providing exceptional accuracy. The 16.1-inch configuration (5.75 pounds) offers a compact, maneuverable option well-suited for hunting, duty, and general-purpose applications.
The 18-inch model (5.9 pounds) delivers increased muzzle velocity and enhanced performance at extended distances. When fed with quality match ammunition, both configurations are backed by the PWS sub-MOA accuracy guarantee.
For shooters who already have a compatible lower receiver, it’s easy to add new capabilities without buying another complete rifle. Whether switching between suppressed and unsuppressed setups or choosing the barrel length that best fits the job, the modular design gives you the flexibility to customize your shooting experience without adding unnecessary equipment.
At each complete upper assembly’s heart is the PWS long-stroke piston operating system, which features a three-position adjustable gas regulator. Engineered from the outset for reliable suppressed and unsuppressed performance, the system vents excess gas forward to minimize receiver fouling, reduce operating temperatures, and improve overall shooter comfort during extended firing sessions.
The patent-pending PWS Bore Evacuator is designed to enhance suppressor performance by using an expansion chamber and the Venturi effect to redirect excess gas at the muzzle, creating a cleaner, more refined shooting experience.
Each complete upper features a 7075-T651 forged proprietary MOD 2-M upper receiver with forward assist that’s paired with a semi-monolithic, seven-sided, free-float M-LOK handguard for improved rigidity and consistent accuracy.
The included FRC 3 Port compensator, with its tapered-shoulder design, helps mitigate recoil and flash while remaining compatible with PWS PUB suppressor mounts and other common HUB taper mount adapters. The complete assembly is finished in a durable MIL-A-8625 Type III hardcoat anodizing for long-lasting performance in demanding environments.
Each complete upper arrives fully assembled and ready to install on a compatible lower, so you can quickly configure for hunting, duty, precision shooting, or suppressed applications. By pairing multiple complete uppers with an existing lower, you’ll expand your capabilities while reducing the cost, storage space, and transport requirements associated with maintaining multiple complete rifles.
Combined with the proven PWS long-stroke piston operating system, premium components, and sub-MOA accuracy guarantee, the MK2 MOD 2 Complete Uppers provide a versatile solution for shooters seeking dependable performance across a wide range of missions.
Primary Weapons Systems
MK2 MOD 2 Complete Uppers
MSRP: $1,800
URL: primaryweapons.com
