PRO2A 11.5" 5.56 NATO 1/7 Carbine Length Melonite Upper Kit | Pro2A Tactical

PRO2A 11.5" 5.56 NATO 1/7 Carbine Length Melonite AR-15 Upper Kit

The Sweet Spot of CQB Performance and Reliability in an All-In-One Assembly Package

Achieve the ultimate balance between short-barrel maneuverability and weapon cycling reliability. The PRO2A 11.5" 5.56 NATO Carbine-Length Melonite AR-15 Upper Kit is a comprehensive tactical package that bundles a complete precision upper receiver assembly, a premium Mil-Spec bolt carrier group (BCG), an aluminum charging handle, a full lower parts kit, and a standard blade assembly. Engineered around a highly sought-after 11.5-inch 4150 CMV steel barrel treated with a hard Melonite finish, this kit provides a major step up in system pressure stability over standard 10.5-inch builds. This complete bundle contains every premium internal and external component required to turn your stripped lower receiver into a highly accurate personal defense weapon (PDW). Proudly 100% designed, machined, and precision-tested in the USA.

Key Features

All-In-One Premium Build Package: Takes the guesswork out of matching components. This master kit ships with a matching bolt carrier group (BCG), charging handle, lower parts kit, and adjustable blade assembly pre-inspected for exact interface integration.
Extended 11.5" Gas Dwell Time: The extra inch of barrel past the gas port yields roughly 40% more dwell time than a standard 10.5" barrel. This lowers internal carrier velocities, stabilizes cyclic performance, and results in a significantly softer recoil impulse.
Melonite/Nitride Barrel Protection: The heavy-duty 4150 CMV steel barrel is fully treated with an advanced Salt Bath Melonite finish inside and out. This high-grade hardening process vastly extends barrel life against aggressive gas erosion and shields components from harsh environments.
Aggressive 1:7 Twist Rate Profile: Precision button-rifled with a fast 1:7 twist configuration engineered to stabilize heavy duty tactical and military-grade projectiles—such as 62-grain and 77-grain match varieties—maintaining structural consistency at distance.
Slim Profile Free-Float M-LOK Rail: Built from durable 6061-T6 aluminum, the free-float handguard completely isolates barrel vibrations to preserve uniform mechanical accuracy while offering extensive modular M-LOK attachment space.

Technical Specifications

Upper Receiver	Mil-Spec Forged 7075-T6 Aluminum, M4 Feed Ramps, Type III Hardcoat Anodized Black Finish (Forward Assist & Ejection Port Cover Pre-Installed)
Bolt Carrier Group	Premium M16 Profile Mil-Spec BCG, Nitride/Melonite Finish, Gas Key Properly Staked
Charging Handle	Standard Mil-Spec Aluminum Charging Handle
Barrel Length & Steel	11.5 Inch Profile, 4150 Chrome Moly Vanadium Steel, Medium Contour, Melonite Treated
Caliber	5.56 NATO (Compatible with .223 Remington ammunition)
Twist Rate	1:7 Twist (Optimized to stabilize heavy duty 62gr, 69gr, and 77gr tactical loads)
Gas Operating Block	Carbine-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 with Crush Washer Pre-Installed
Handguard	10 Inch Slim Profile Free-Float M-LOK Rail, Machined from 6061-T6 Aluminum
Lower Parts Kit	Mil-Spec Polished Trigger & Hammer, Standard Pistol Grip, Lower Component Springs, and Pins Included
Brace	Standard Blade with pistol buffer tube, 3oz standard buffer, buffer spring, latch plate, and castle nut
Manufacturing Origin	100% Made in the USA with Pro2A Tactical Lifetime Factory Warranty

Why Choose This Product?

The PRO2A 11.5" 5.56 NATO Carbine Length Upper Kit solves the primary engineering issue found in modern compact AR builds: weapon over-gassing. Military and professional tactical operators widely favor the 11.5-inch profile because it scales down the traditional length of a rifle while preserving a larger window of internal gas dwell time. This choice significantly limits parts wear, tames diagnostic gas blowback, and ensures extraction stability when running standard field ammunition.

By opting for a complete build configuration rather than piecing your firearm together block-by-block, you guarantee that everything functions smoothly. Every component—from the custom-contoured barrel to the matching trigger components—is factory verified for seamless operation. Backed completely by Pro2A Tactical's signature Lifetime Factory Warranty and engineered with 100% American craftsmanship, this master kit allows you to deploy a premium, defensive-ready firearm with absolute building confidence.

More Information