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Primary Weapons Systems MK111 Mod 2-M .223 Wylde 11.85" Piston Upper Receiver - MK1M2U22311
Product Description
Deploying a short-barreled rifle (SBR) or an AR pistol variant configuration under sustained operational or suppressed pacing exposes an immediate physical bottleneck: direct impingement gas limits. Standard short-barreled uppers blast blistering carbon-slurry gases and abrasive particulate directly back inside the bolt group, cooking away critical lubrication and inducing rapid bolt-lug fatigue. Furthermore, running restricted suppressed backpressure lanes spikes receiver temperatures, throwing foul oil spray toward the operator's face while severely disrupting action timing cycles. The Primary Weapons Systems (PWS) **MK111 Mod 2-M Complete Upper Receiver** completely eliminates these cycle-tracking liabilities, stepping past traditional gas-tube arrays to implement an ultra-rugged, long-stroke gas piston engine purpose-built to deliver cleaner operation and flatter recovery splits.
Precision-forged from premium 7075-T651 structural aerospace aluminum alloy, the Mod 2-M upper is protected by a uniform, non-reflective MIL-SPEC Type III Class 2 hardcoat anodized jacket that actively deflects field scrapes, corrosive cleaning compounds, and carbon scale. At its core is an elite 11.85-inch 41V50 Chrome-Moly Vanadium steel barrel, custom button-rifled with a precise 1:8 twist rate and chambered in optimized **.223 Wylde**. This engineering refinement easily tolerates high-pressure 5.56mm NATO duty ammunition and precision commercial .223 Remington loads with equal ease, pushing projectile stabilization out to its maximum ballistic yield. By matching this premium barrel to PWS’s proprietary long-stroke piston core, the kinetic push mirrors an M14 or AK-47 operating layout—distributing cyclic pressures along a single unibody rod assembly to reduce felt bolt-bounce and keep the bolt cavity up to 80% cleaner than legacy systems.
In high-velocity defensive pacing or dynamic vehicle-mounted assignments, this optics-ready platform expands your tactical adaptability. It introduces a highly sophisticated **3-setting adjustable gas regulator block**, enabling the shooter to dial in gas-vent restrictions to balance system cycling whether running unsuppressed ammunition profiles, standard suppressor loads, or heavy sub-sonic duty configurations. Up front, the sleek 11-inch **PicLok™ free-float handguard** provides a unique hardware solution, integrating a standard top Picatinny section with side and lower windows that host both direct M-LOK components and recessed Picatinny rail tracks natively. Complete with a Radian Raptor™ ambidextrous charging handle and a suppressor-ready PWS FRC 2-Port compensator, this Boise-made upper is a highly reliable option for modern SBR builds.
*Armorer Bench Notes & Technical Maintenance Guidance: The MK1M2U22311 complete upper group drops natively onto any standard mil-spec AR-15 lower receiver assembly. Because this package features an 11.85-inch barrel array, it is classified as an NFA short-barreled component; you must satisfy all local and federal NFA regulations if pinning this upper to a standard lower housing outfitted with a shoulder stock. When dialing your gas settings via the front regulator notch, utilize the included PWS gas tool or a standard cartridge rim: Position 1 tunes gas flow for normal unsuppressed tracking, Position 2 dials back cyclic pressure for standard suppressor configurations, and Position 3 restricts flow heavily to balance highly efficient, high-backpressure silencers or hot duty-grade loads. Due to the inherent forward-shifting center of gravity of long-stroke piston rods, pair this upper with an enhanced H2 steel-body buffer or an adjustable spring matrix to maximize recoil softening and capture smooth slide-lock tracking profiles.
Key Features
- PWS Long-Stroke Piston Core: Keeps carbon fouling and intense chamber heat completely isolated from the bolt carrier group to eliminate sluggish cycling errors.
- 3-Position Adjustable Gas Block: Click-adjustable gas valve lets operators tailor cyclic speeds for suppressor integration, environmental shifts, and changing ammunition pressures.
- Precision .223 Wylde Profile: Meticulously chambered to extract maximum long-range accuracy and absolute feed safety from both 5.56 NATO and .223 Rem payloads.
- Innovative PicLok™ Handguard: Combines universal M-LOK mounting slots and structural Picatinny tracks into a single flush-face layout for clean, bulk-free accessory tracking.
- Premium Hardware Furnished: Ships factory-equipped with a premium Radian Raptor™ ambidextrous charging handle and a Rearden Atlas-compatible FRC 2-Port compensator.
Product Specifications
- Brand: Primary Weapons Systems (PWS)
- Model Line: MK1 MOD 2-M High-Performance Piston Series
- MPN/SKU: MK1M2U22311
- UPC: 811154033208
- Receiver Chassis Material: Forged 7075-T651 Aerospace Aluminum Billet (No Forward Assist)
- Chassis Exterior Finish: MIL-SPEC Type III Class 2 Hardcoat Anodization (Matte Black)
- Operating System Type: Long-Stroke Piston Engine (Carbine Length Gas Track)
- Barrel Composition: 41V50 Chrome-Moly Vanadium Structural Steel (M4 Feed Ramps)
- Barrel Length: 11.85 Inches
- Barrel Twist Rate: 1:8 Twist Configuration
- Muzzle Device Interface: PWS FRC 2-Port Compensator (1/2x28 Thread - Rearden Atlas Ready)
- Handguard System: 11.0" PicLok Free-Float Rail System
- Sighting Interface Profile: Continuous Top Picatinny Rail (Optics Ready Baseline)
- Charging Interface: Radian Raptor™ Ambidextrous Assembly
- Overall Assembly Mass: 4.0 lbs (Unloaded Upper Weight)
- Country of Manufacture: United States (Boise, Idaho)
