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RISE Armament Watchman XR 6mm ARC 18 Inch Complete Upper Receiver Assembly Sniper Grey RA 6ARC CU GRY 18 UPC 850043415961
Product Description
The RISE Armament® Watchman XR 18" 6mm ARC Complete Upper Receiver Assembly in Sniper Grey (SKU: RA-6ARC-CU-GRY-18 / UPC: 850043415961) is an elite, match-grade long-range system engineered to maximize the flat trajectory and ballistic efficiency of Hornady’s 6mm ARC cartridge on the AR-15 chassis. Purpose-built for PRS gas-gun competitors, precision predator hunters, and DMR field applications, this fully assembled upper receiver transforms standard lower receivers into precision instruments capable of repeatable sub-MOA performance beyond 1,000 yards.
At the core of this system is an 18-inch 416R stainless steel barrel precision-buttoned with a fast 1:7 twist rate, engineered to stabilize heavy 103-grain to 108-grain high-BC factory match ammunition. The barrel is seated into a 7075-T6 forged billet aluminum receiver finished in protective Sniper Grey Cerakote for maximum resistance to abrasion, chemical solvents, and high thermal cycles. Cycling is driven by a factory-tuned black nitride bolt carrier group containing an 8620 steel carrier, an individually MPI-inspected 9310 alloy steel bolt, and properly torqued, staked gas key fasteners to resist carbon build-up and carrier wear.
Surrounding the barrel is a 15.25-inch lightweight free-float M-LOK handguard that completely isolates barrel harmonics while offering mounting real estate along the 3, 6, and 9 o'clock planes for match bipods, barricade stops, and weapon-mounted accessories. Paired with a rifle-length direct-impingement gas system that softens the recoil impulse and extends bolt unlock dwell time, the upper comes fully equipped with a RISE ambidextrous charging handle to facilitate fast, effortless weapon charging and malfunction clearing from either shoulder.
*Armorer Bench Notes & Real-World Staging Guidance:*
Fitment Matrix: Direct drop-in fit for standard Mil-Spec AR-15 forged or billet lower receivers. CRITICAL: Requires dedicated 6mm ARC or 6.5 Grendel pattern AR-15 magazines for reliable feeding; do not attempt to feed through standard 5.56 NATO/.223 magazines. Note muzzle thread pitch is 1/2x28 UNEF-2A; ensure any aftermarket muzzle brake, compensator, or suppressor direct-thread mount features an aperture cleared for 6mm/.243 caliber projectiles before torquing to 20-25 ft-lbs with a crush washer or shim kit.
- Ensure the host AR-15 lower receiver is visually and physically verified empty, magazine removed, and hammer rested in the forward uncocked position.
- Inspect the pre-installed RISE black nitride bolt carrier group and ambidextrous charging handle, ensuring proper lubrication on all carrier bearing rails and cam pin raceways.
- Push out the front pivot and rear takedown pins on your host lower receiver, position the upper receiver front lug into the pivot pocket, and press the pivot pin fully closed.
- Hinge the upper receiver down onto the lower receiver deck and seat the rear takedown pin flush into its detent channel.
- Perform a comprehensive five-point dry-fire function check, confirm proper bolt lock-back on an empty 6mm ARC magazine, and verify muzzle alignment with a concentricity rod prior to live-fire range zeroing.
Key Features
- Match-Grade 416R Stainless Steel: 18-inch precision-buttoned barrel with a 1:7 twist rate delivers supreme stabilization for high-BC 6mm bullets in extreme long-range applications.
- Rifle-Length Gas System: Significantly reduces carrier velocity and felt recoil, yielding smooth cycling, minimal sight picture disruption, and extended brass life.
- Sniper Grey Cerakote Finish: Premium H-Series ceramic coating over 7075-T6 forged billet aluminum provides elite corrosion, heat, and chemical resistance.
- 15.25-Inch Free-Float M-LOK Handguard: Maximum barrel harmonics isolation with modular mounting points for match bipods, barrier stops, and night vision devices.
- Complete Factory BCG & Ambi Charging Handle: Outfitted with an MPI-tested 9310 black nitride bolt assembly and RISE ambi charging handle for out-of-the-box readiness.
Product Specifications
- Brand: RISE Armament®
- Model/Series: Watchman XR 6mm ARC Complete Upper Receiver
- MPN / SKU: RA-6ARC-CU-GRY-18 / RA6ARCCUGRY18
- UPC: 850043415961
- Platform Compatibility: Standard Mil-Spec AR-15 Lower Receivers
- Country of Origin: United States of America
