Pro2A Tactical

PRO2A 20" 5.56 NATO 1/7 Rifle Length Melonite M-LOK AR-15 Upper

Ultimate Muzzle Velocity & Smooth Rifle-Length Cycling

Maximize the ballistic potential of the 5.56 cartridge with the PRO2A 20" 5.56 NATO Rifle-Length AR-15 Upper Receiver. Engineered for marksmen who refuse to compromise on velocity or reliability, this upper assembly combines a full-length 20-inch barrel with a smooth rifle-length gas system. It drops natively onto any standard Mil-Spec AR-15 lower receiver, delivering a soft recoil impulse and flat shooting performance. Proudly 100% designed, machined, and meticulously assembled in the USA.

Key Features

Melonite Barrel Longevity: The 4150 CMV steel barrel is treated inside and out with a premium Nitride/Melonite finish. This provides superior corrosion resistance, cleaner maintenance, and extended barrel life over traditional chrome lining without compromising match-grade accuracy.
Fast 1:7 Twist Rate: The versatile 1:7 twist pattern is optimized to stabilize heavy, long-range projectiles—such as 69-grain, 75-grain, and 77-grain match loads—while cleanly shooting standard 55-grain target ammo.
Rifle-Length Gas System: Experience the softest possible recoil impulse. The increased dwell time of a true rifle-length gas system reduces internal pressure spikes, limits parts wear, and keeps your sight picture perfectly steady for rapid follow-up tracking.
Free-Float 15-Inch M-LOK Handguard: Built from durable 6061-T6 aluminum, the slim-line handguard eliminates barrel stress for enhanced mechanical accuracy while providing plenty of real estate for M-LOK accessories and a full top Picatinny rail.

Technical Specifications

Upper Receiver	Mil-Spec Forged 7075-T6 Aluminum, M4 Feed Ramps, Type III Hardcoat Anodized Black (Forward Assist & Ejection Port Cover Pre-Installed)
Barrel Length & Profile	20 Inch, Government/Medium Profile
Caliber Chambering	5.56 NATO (Fully backward compatible with .223 Remington)
Twist Rate Matrix	1:7 Twist
Gas Operating Block	Rifle-Length System, Low-Profile Gas Block Machined from 4140 Steel, Stainless Steel Gas Tube
Muzzle Device Config	Standard 1/2-28 Thread Pitch, A2 Birdcage Flash Hider with Crush Washer
Handguard Rails	15" Free-Float M-LOK Rail, Slim Profile, Machined from 6061-T6 Aluminum
Manufacturing Origin	100% Made in the USA with Lifetime Factory Warranty

Who Chooses This Upper Receiver?

Long-Range Marksmen & Bench Shooters

Enthusiasts looking to stretch the legs of the 5.56 NATO cartridge choice rely on a 20-inch barrel to gain up to 150-200 FPS of extra muzzle velocity over standard 16-inch setups. This translates directly to a flatter trajectory and less wind drift at extended ranges.

Soft-Recoil Traditionalists

Shooters who appreciate a smooth operating cycle love the mechanical harmony of a 20-inch barrel combined with a rifle-length gas tube. The configuration drastically decreases bolt carrier velocity for a pleasant, low-concussion shooting experience.

Home Builders & Coyote Hunters

Varmint hunters and custom builders wanting a reliable, drop-in assembly prefer this setup. It avoids the headaches of tuning raw parts at home while offering an american lifetime factory guarantee.