PRO2A LEFT HAND 13.7" 5.56 NATO 1/7 Mid Length Melonite M-LOK AR-15 Upper

Product Overview

The PRO2A LEFT HAND 13.7" 5.56 NATO 1/7 Mid Length Melonite M-LOK AR-15 Upper is a mirror-engineered, standalone top-end assembly purpose-built to deliver premium ergonomics for left-handed operators. Centered around a **dedicated Left-Eject forged receiver**, this assembly moves the ejection path away from standard layouts to keep spent casings and blowback gas safely clear of left-dominant shooters. The 13.7-inch barrel length is highly coveted by custom builders seeking the absolute shortest possible footprint that can be permanently pinned-and-welded to reach legal rifle constraints.

Key Features

True Left-Hand Architecture: Engineered with a dedicated left-side ejection port to prevent face-directed hot brass and gas blowback exposure for southpaw shooters.
Ideal Pin & Weld Length: The 13.7-inch configuration offers elite compact agility, serving as the perfect foundation for a legal 16-inch overall rifle build when pinned and welded with an extended muzzle device.
Smooth Mid-Length Gas Subsystem: Delivers a softer recoil pulse, lowered pressure peaks, and reduced internal component wear compared to harsh, over-gassed carbine setups.
Military-Grade 1:7 Twist Profile: Highly optimized to reliably stabilize heavier tactical projectiles (such as 62gr, 69gr, and 77gr duty loads) over extended operational envelopes.
Sub-Surface Melonite QPQ Armor: Liquid-immersion nitriding infuses deep surface protection across the 4150 CMV steel barrel core, safeguarding critical lands and grooves from harsh throat attrition and environmental humidity.
Free-Floating M-LOK Handguard: Features a slim-profile modular rail system aligned flat with the upper receiver top rail, optimizing accessory placement without shifting your barrel's point of impact.

Technical Specifications

Upper Receiver	Milspec Billet Aluminum, Dedicated Left-Hand Ejection Port, M4 Feed Ramps, Type III Hardcoat Anodized Black
Barrel Length & Profile	13.7-Inch Medium Profile
Caliber	5.56 NATO (Accepts .223 Remington)
Twist Rate	1:7 Twist Rate (Optimized for heavy grain tracking and duty round stabilization)
Barrel Material	4150 Chrome Moly Vanadium Steel with Premium Melonite/QPQ Treatment
Gas System	Mid Length Direct Impingement with Low-Profile Gas Block
Handguard	12-Inch Free Float Slim Profile M-LOK Rail System (Aligns seamlessly with flat-top receiver)
Muzzle Device	Standard A2 Flash Hider (1/2x28 Thread Pitch - Non-Pinned)

Why Choose This Product

This standalone 13.7-inch barreled upper receiver assembly provides a highly specialized platform that completely modernizes left-handed shooting dynamics while catering directly to enthusiasts looking for a compact, non-NFA rifle build pipeline. Proudly manufactured in the USA to unrelenting tactical tolerances, it delivers reliable field accuracy right out of the box.

More Information