PRO2A LEFT HAND 18" 6.5 Grendel 1/8 Mid Length Melonite M-LOK AR-15 Upper

Mid-Range Precision and Soft Recoil Engineered for the Left-Handed Marksman

Bridge the gap between lightweight mobility and long-range ballistic performance without typical right-hand frame compromises. The PRO2A Left Hand 18" 6.5 Grendel Mid-Length Upper Receiver Assembly is engineered from the ground up for southpaw shooters who demand maximum mechanical precision. Featuring a dedicated, mirrored left-eject port layout, this upper completely redirects spent casings, hot unburnt powder, and high-pressure gases away from a left-handed operator's face. Built around a versatile 18-inch barrel configuration to optimize the velocity footprint of the 6.5 Grendel cartridge, it delivers a flat downrange trajectory and high kinetic energy retention. Paired with a smooth mid-length gas system, this premium upper drops natively onto any Mil-Spec lower receiver to anchor a highly accurate, incredibly balanced rifle build. Proudly 100% designed, machined, and hand-assembled in the USA.

Key Features

True Left-Hand Port Architecture: Specifically mirrored receiver geometry handles the manual extraction pathway smoothly, throwing spent brass out of the left side to eliminate facial debris, distracting flashes, and blowback common with right-handed setups.
Optimized 18-Inch Barrel Velocity: The 18-inch barrel profile wrings out complete powder combustion for optimized muzzle velocity over standard 16-inch setups, extending your effective ethical range while preserving nimble, balanced target tracking.
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, aids in uniform thermal dissipation, and shrugs off harsh outdoor elements.
Reliable Mid-Length Gas Tuning: Formed with a low-profile gas block and a mid-length gas system configuration to optimize internal bolt velocities and dwell time, establishing highly reliable cycling paths across dynamic cartridge pressures.
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

Receiver & Ejection Type	Dedicated Left Hand (Left Eject), Billet Aluminum, M4 Feed Ramps, Type III Hardcoat Anodized Black
Barrel Length & Profile	18 Inch Profile, 4150 Chrome Moly Vanadium Steel, Medium Profile Contour
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	Mid-Length System, Low-Profile Gas Block Machined from 4140 Steel, Stainless Steel Gas Tube
Muzzle Device Config	Standard 5/8-24 Thread Pitch, 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?

Southpaw Medium-to-Long Range Competitors

Marksmen looking to compete with an inherently precise cartridge on an affordable small-frame layout select this 18-inch 6.5 Grendel setup. It provides ballistic performance that minimizes wind drift while remaining pleasant to shoot over long tournament strings.

Left-Handed Mobile & Tree Stand Hunters

Deer, hog, and open-country predator hunters who need ethical energy drop-offs past 300 yards rely on the 18-inch configuration. The mirror-ejection layout ensures that quick follow-up shots are taken without hot brass or heavy smoke getting blown into the shooter's eyes.

Suppressed Southpaw Precision Builders

Left-hand shooters assembling a precision build meant to carry a silencer benefit heavily from a dedicated left-eject port. Paired with a smooth gas system configuration, it redirects increased backpressure completely away from the shooter's breathing space.