PRO2A LEFT HAND 14.5" 5.56 NATO 1/7 Mid Length Melonite M-LOK AR-15 Upper

True Left-Hand Ejection Meets Lightweight Maneuverability

Stop breathing in gas and looking at brass flying across your face. The PRO2A Left Hand 14.5" 5.56 NATO Mid-Length Upper Receiver Assembly is purpose-built from the ground up for southpaw shooters. Featuring a dedicated left-ejecting receiver profile and a high-mobility 14.5-inch barrel configuration, this upper drops natively onto any standard left-handed or ambidextrous lower receiver build. It pairs beautifully with the soft-shooting recoil metrics of a mid-length gas system to deliver optimal handling, tactical balance, and flat-shooting tracking. Proudly 100% designed, machined, and precision-assembled in the USA.

Key Features

Dedicated Left-Hand Architecture: Features a mirrored port design that ejects spent brass cleanly out of the left side of the upper, redirecting debris and blowback away from left-handed shooters' eyes and faces.
Melonite/Nitride Barrel Protection: The heavy-duty 4150 CMV steel barrel is treated inside and out with a premium Melonite/Nitride finish. This hardening process vastly extends barrel life, aids in heat dissipation, and increases corrosion resistance over standard chrome lining.
Fast 1:7 Twist Rate Profile: Optimized to safely stabilize heavier, match-grade, and duty ammunition choices—including 62-grain, 69-grain, and 77-grain projectiles—while retaining clean downrange performance with standard 55-grain loads.
Mid-Length Gas System Dynamics: Mitigates harsh cyclic pressure spikes. The increased dwell time of a mid-length gas layout slows bolt carrier speed, noticeably dampening felt recoil while decreasing internal component wear over time.
Slim-Line Free-Float M-LOK Rail: Machined from premium 6061-T6 aluminum, the handguard isolates barrel stress to optimize mechanical accuracy while offering ample M-LOK accessory attachment space and a top Picatinny rail layout.

Technical Specifications

Receiver	Dedicated Left Hand (Left Eject), Billet Aluminum, M4 Feed Ramps, Type III Hardcoat Anodized Black
Barrel Length & Profile	14.5 Inch Medium Weight Profile
Caliber	5.56 NATO (Safely shoots both 5.56x45mm and .223 Remington ammunition)
Twist Rate	1:7 Twist
Gas Operating System	Mid-Length System, Low-Profile Gas Block Machined from 4140 Steel, Stainless Steel Gas Tube
Muzzle Device	Standard 1/2-28 Thread Pitch, A2 Birdcage Flash Hider
Handguard	12" Free-Float M-LOK Rail, Slim Profile, Machined from 6061-T6 Aluminum
Manufacturing Origin	100% Made in the USA with Pro2A Tactical Lifetime Factory Warranty

Who Chooses This Upper Receiver?

Left-Handed Operational Shooters

Southpaw marksmen tired of compromising on standard right-handed rifles choose this dedicated left-eject setup to keep escaping gas, burning powder residue, and hot brass completely out of their peripheral line of sight.

Tactical Carbine Builders

Enthusiasts building a fast-handling general-purpose rifle value the 14.5-inch barrel weight distribution. It provides an ideal balance of muzzle velocity and quick mobility inside enclosed or high-intensity training spaces.

Suppressed Southpaw Builders

Left-hand shooters planning to host a suppressor benefit heavily from a left-hand port layout. Suppressors drastically increase backpressure, and a left-ejecting receiver prevents that concentrated gas from venting directly into the shooter's face.