Pro2A Tactical

PRO2A 18" 5.56 NATO 1/8 Mid Length Melonite M-LOK AR-15 Upper

Premium Soft-Shooting AR-15 Upper Receiver Assembly

Upgrade your platform with the PRO2A 18" 5.56 NATO Mid-Length AR-15 Upper Receiver. Combining the extended barrel velocity of an 18-inch profile with the reliable, reduced-dwell-time cycling of a mid-length gas system, this complete upper receiver drops natively onto any standard Mil-Spec AR-15 lower. Proudly 100% designed, machined, and assembled in the USA.

Key Features

Melonite Barrel Protection: The 4150 CMV steel barrel features a complete Nitride/Melonite finish inside and out, exponentially increasing barrel life, heat dissipation, and weather resistance over traditional chrome lining.
Versatile 1:8 Twist Rate: The 1:8 stabilizing twist cleanly handles a massive weight matrix of projectiles, stabilizing everything from standard 55-grain target loads up to heavy 77-grain match-grade bullets flawlessly.
Mid-Length Gas System Dynamics: Delivers a softer recoil pulse, reduced internal part wear, and flatter muzzle tracking compared to overly aggressive carbine-length gas layouts.
15-Inch Slim M-LOK Handguard: Features an ultra-strong 6061-T6 aluminum free-float handguard providing continuous top rail spacing alongside generous M-LOK attachment slots at key angles.

Technical Specifications

Upper Receiver	Mil-Spec Forged 7075-T6 Aluminum, M4 Feed Ramps, Type III Hardcoat Anodized Black (Forward Assist & Ejection Port Cover Installed)
Barrel Length & Profile	18 Inch, Medium Profile Profile
Caliber Chambering	5.56 NATO (Safely fires both 5.56x45mm and .223 Remington)
Twist Rate Matrix	1:8 Button Rifled Twist
Gas Operating Block	Mid-Length System, Low-Profile Gas Block Machined from 4140 Steel, Stainless Gas Tube
Muzzle Device Config	Standard 1/2-28 Threads, A2 Birdcage Flash Hider with Crush Washer
Handguard Rails	15" Free-Float M-LOK Rail, Machined from 6061-T6 Aluminum
Manufacturing Origin	100% Made in the USA with Lifetime Factory Warranty

Who Chooses This Upper Receiver?

3-Gun & Practical Competitors

Shooters seeking quick transition tracking and flatter target muzzle stability prefer this 18-inch barrel configuration combined with a smoother-shooting mid-length recoil system to keep their optics locked on downrange targets.

Varmint Hunters & Predator Control

Hunters who require maximum muzzle velocity to extend their ethical effective range past 300 yards without dragging the bulk or heavy profile of a full 20-inch rifle system out into the field.

Piecemeal Benchrest Builders

Custom gunsmiths and enthusiasts building a long-range plinker who prefer a drop-in ready, range-tested assembly backed by an american lifetime warranty instead of hand-tuning gas parts at home.