PRO2A 16" 300 Blackout 1/7 Pistol Length Melonite AR-15 Upper Kit

Full-Length Rifle Legality Meets Maximum 300 BLK Subsonic & Supersonic Cycling Reliability

Deploy the heavy-hitting 300 AAC Blackout cartridge from a standard, non-NFA rifle configuration without compromising mechanical cycling pressures. The PRO2A 16" 300 Blackout Pistol-Length Melonite AR-15 Upper Kit is a comprehensive all-in-one assembly package containing a complete precision upper receiver assembly, a premium Mil-Spec bolt carrier group (BCG), a standard aluminum charging handle, a complete lower parts kit, and a 6-position adjustable stock assembly. Engineered specifically with a pistol-length gas system on a full 16-inch barrel, this configuration maximizes internal gas pressure dwell time. This guarantees reliable cycling with everything from low-recoil subsonic loads to high-velocity supersonic hunting cartridges. This component bundle includes everything required to easily transform your stripped lower receiver into a finished tactical carbine. Proudly 100% designed, machined, and precision-tested in the USA.

Key Features

All-In-One Complete Rifle Build Package: Takes the technical guesswork out of assembly. This master kit ships complete with a matching bolt carrier group (BCG), charging handle, polished trigger assembly, lower parts kit, and an adjustable stock setup pre-inspected for exact interface integration.
Optimized Pistol-Length Gas Matrix: Unlike standard 5.56 rifles, the fast-burning powder of the 300 Blackout round requires a pistol-length gas port to harvest reliable cycling energy, ensuring positive extraction across an incredibly wide range of ammunition variants.
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 premium chemical hardening vastly extends bore life against rapid gas erosion and defies harsh outdoor moisture.
Aggressive 1:7 Twist Rate Profile: Precision button-rifled with a fast 1:7 twist rate configuration engineered to perfectly stabilize heavy subsonic tactical weights up to 220-grain while maintaining excellent grouping consistency with lighter supersonic options.
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	16 Inch Profile, 4150 Chrome Moly Vanadium Steel, Medium Contour, Melonite Treated
Caliber	300 AAC Blackout (7.62x35mm)
Twist Rate	1:7 Twist (Optimized to stabilize standard, heavy tactical subsonic, and hunting projectile loads)
Gas Operating Block	Pistol-Length System, Low-Profile Gas Block Machined from 4140 Steel, Stainless Steel Gas Tube
Muzzle Device	Standard 5/8-24 Thread Pitch, A2 Flash Hider with Crush Washer
Handguard	12 Inch Slim Profile Free-Float M-LOK Rail, Competition Top Picatinny Rail, Machined from 6061-T6 Aluminum
Lower Parts Kit	Mil-Spec Polished Trigger & Hammer, Standard Pistol Grip, Lower Component Springs, and Pins Included
Stock	Standard Mil-Spec M4 Stock with 6-position buffer tube, standard 3oz 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 16" 300 Blackout Upper Kit solves the largest operational challenge encountered when running a full-length 300 BLK platform: finding the cycling balance between distinct bullet weights. While short barrels are commonly associated with the cartridge, choosing a full 16-inch barrel frees you from the legal complexities of NFA pistol braces and short-barreled rifle registrations. By anchoring this 16-inch configuration around a true pistol-length gas system, Pro2A Tactical provides maximum reliability, supplying plenty of pressure to cycle stubborn subsonics cleanly while maintaining smooth dwell times for supersonic 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 and weighted buffer system—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.