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Primary Weapons Systems is bringing its long-stroke piston system to more large-frame AR owners.
The company introduced its new MK2 MOD 2 Complete Uppers in 16.1-inch and 18-inch configurations. Both models chamber .308 Winchester and arrive ready for installation on a compatible lower receiver.
The idea is simple. Shooters can add a suppressed, hunting or precision setup without buying another complete rifle.
Two .308 Configurations
The 16.1-inch MK216 MOD 2 weighs 5.75 pounds. Its shorter barrel makes it the more maneuverable option for hunting, duty use and general-purpose builds.
The 18-inch MK218 MOD 2 weighs 5.9 pounds. That additional barrel length should provide more velocity and better performance at longer distances.
Both versions use a 416R stainless steel barrel with a 1:10 twist. That twist rate can stabilize a wide range of popular .308 bullet weights.
PWS also backs both uppers with a sub-MOA accuracy guarantee when used with quality match ammunition.
Built for Suppressors
Each upper uses the company’s long-stroke piston operating system and three-position adjustable gas regulator.
The system can accommodate suppressed and unsuppressed shooting. It also vents excess gas forward, helping reduce heat and fouling inside the receiver.
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PWS includes its patent-pending Bore Evacuator as well. The system uses an expansion chamber and the Venturi effect to redirect excess gas near the muzzle.
That should mean less gas reaching the shooter during suppressed fire.
Both uppers include an FRC three-port compensator. Its tapered shoulder works with PWS PUB suppressor mounts and other common HUB taper-mount adapters.
Complete and Ready to Install
PWS builds each upper around a proprietary 7075-T651 forged MOD 2-M receiver with a forward assist.
A seven-sided, semi-monolithic M-LOK handguard provides a rigid free-floating platform for accessories. The entire assembly receives a MIL-A-8625 Type III hardcoat-anodized finish.
The uppers arrive fully assembled. However, buyers should confirm lower-receiver compatibility with PWS before ordering. Large-frame AR components do not share the same universal dimensions found across many smaller AR-15 platforms.
The MK216 and MK218 MOD 2 Complete Uppers are available now. Both carry an MSRP of $1,799.95.
For additional specifications and availability, visit Primary Weapons Systems.
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is a seasoned outdoorsman, lifelong hunter, and the kind of guy who’d rather track whitetails than scroll social media. As an editor for GunsAmerica, he’s got a sharp eye for spotting both solid gear and bad gun laws. Whether he’s deep in the woods or deep in editorial deadlines, Larry brings a no-nonsense, tell-it-like-it-is approach to firearms, hunting, and the great American tradition of self-reliance. If there’s a hot debate on gun rights or the latest in hunting tech, you can bet Larry’s got an opinion—and it’s probably backed up with both facts and field experience.
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