PRO2A 20" 6.5 Grendel Rifle Length NR Side Charging Melonite M-LOK AR-15 Upper

Maximum Downrange Energy Meets Elite Ergonomic Control

Squeeze every ounce of ballistic velocity out of the inherently precise 6.5 Grendel cartridge while transforming your platform's manual of arms. The PRO2A 20" 6.5 Grendel Rifle-Length Non-Reciprocating (NR) Side Charging Upper Assembly updates traditional AR-15 operations by moving the charging handle to a heavy-duty, left-side cocking lever. The handle stays fully stationary during live-fire cycling, providing a seamless operating zone free from moving external components near your optic mount. Built around an extended 20-inch 4150 CMV barrel, this configuration maximizes complete powder burn to drive heavy projectiles with flatter trajectories and higher kinetic impact past 800 yards. Drops natively onto any standard Mil-Spec AR-15 lower receiver to anchor a highly precise, soft-recoiling distance setup. Proudly 100% designed, machined, and precision-assembled in the USA.

Key Features

Stationary Side-Charging Handle: The premium non-reciprocating left-side manual handle operates completely independently from the bolt carrier cycle. This allows for fluid charging from prone or benched layouts and completely seals off the rear opening to block high-pressure gases from venting into your face.
Maximized 20-Inch Muzzle Velocity: The extended barrel length ensures complete powder combustion, driving heavier 6.5 Grendel projectiles to their optimal factory velocities to stretch out ethical hunting distances and optimize downrange ballistics.
Melonite/Nitride Barrel Protection: The heavy-duty 4150 CMV steel barrel is fully Nitride/Melonite treated inside and out. This premium chemical hardening vastly extends barrel life, optimizes heat dissipation during long strings, and shrugs off harsh outdoor elements.
Smooth Rifle-Length Gas Dwell: Tuning a 20-inch barrel with a true rifle-length gas tube significantly lowers port pressure and slows the bolt carrier cycle. The results are an exceptionally soft recoil pulse, reduced parts fatigue, and effortless sight-picture tracking.
15-Inch Free-Float M-LOK Rail: Built from rigid 6061-T6 aluminum, the slim free-float rail isolates barrel harmonic stress to lock in uniform mechanical accuracy while offering expansive real estate for bipods, lights, and an uninterrupted top Picatinny configuration.

Technical Specifications

Upper Receiver	Gibbz Arms G4 Non Reciprocating Side Charging Billet Aluminum Receiver with Gen 2 Handle, M4 Feed Ramps, Type III Hardcoat Anodized Black
Barrel Length & Steel	20 Inch Medium Profile, 4150 Chrome Moly Vanadium Steel
Caliber	6.5 Grendel Type II (.136" Bolt Face Depth)
Twist Rate	1:8 Twist (Optimized to stabilize common 120gr to 123gr precision projectiles)
Gas Operating Block	Rifle-Length System, Low-Profile Gas Block Machined from 4140 Steel, Stainless Steel Gas Tube
Muzzle Device Config	Standard 6.5 Grendel Thread Pitch (5/8-24 Threads), A2 Flash Hider with Crush Washer
Handguard	15" Slim Profile Free-Float M-LOK Rail, Machined from 6061-T6 Aluminum
Manufacturing Origin	100% Made in the USA with Pro2A Tactical Lifetime Factory Warranty

Who Chooses This Upper Receiver?

Medium-to-Long Range Precision Marksmen

Shooters wanting to push small-frame limits with an inherently precise cartridge select this 20-inch 6.5 Grendel setup. It provides long-distance ballistics that minimize wind drift and drop while remaining exceptionally pleasant to shoot over long strings.

Oversized Optics & Thermal Night Hunters

Predator and hog hunters running bulky low-power variable optics (LPVOs) or wide thermal sights prefer side-charging platforms. The left-mounted handle leaves massive clearance space below the scope base, preventing scraped knuckles against large mounts.

Extended Distance Open-Country Hunters

Deer, antelope, and predator hunters operating across wide pastures rely on the 20-inch profile. The extra length wrings maximum velocity from the cartridge, ensuring high kinetic energy retention and clean, ethical placement out past 300 yards.