PRO2A 10.5" 5.56 NATO 1/7 Carbine Length NR Side Charging Melonite M-LOK AR-15 Upper

The Ideal Balance of Tactical Maneuverability and Ergonomic Control

Upgrade your rifle build with an intuitive, left-side manual manual of arms. The PRO2A 10.5" 5.56 NATO Carbine Length Non-Reciprocating (NR) Side Charging Upper Assembly removes the standard rear charging handle to deliver enhanced clearance and ergonomics. The side-cocking handle remains completely stationary while the system cycles and fires, ensuring it won't interfere with your hands or nearby equipment. Paired with a popular 10.5-inch barrel configuration and a smooth carbine-length gas path, this complete upper receiver drops right onto any Mil-Spec AR-15 lower receiver to construct an incredibly agile pistol or Short Barreled Rifle (SBR). Proudly 100% designed, machined, and precision-assembled in the USA.

Key Features

Stationary Side-Charging Handle: The non-reciprocating handle stays securely in place during live fire. This lets you cycle the weapon seamlessly while maintaining your cheek weld and keeps gas and debris blowing out the rear away from your face.
Melonite/Nitride Barrel Protection: The 4150 CMV steel barrel is fully Nitride/Melonite treated inside and out. This hard-surface treatment provides superior heat dissipation and corrosion defense, ensuring excellent barrel life over thousands of rounds.
Aggressive 1:7 Twist Rate: The 1:7 button-rifled twist rate perfectly stabilizes heavy duty and military-grade projectiles—such as 62-grain and 77-grain match choices—maintaining mechanical reliability out of a short rifling profile.
Reliable Carbine Gas Port Tuning: The carbine-length gas path provides consistent, reliable cycling pressures with standard 55-grain target ammo up to high-pressure defense loads, utilizing a low-profile steel gas block.
Slim Profile Free-Float Handguard: Built from durable 6061-T6 aluminum, the free-float rail isolates barrel harmonic stress for uniform accuracy while offering M-LOK attachment slots and a continuous top Picatinny rail.

Technical Specifications

Upper Receiver	Gibbz Arms G4 Non Reciprocating Side Charging Billet Aluminum Receiver with Gen 2 Handle, M4 Feed Ramps, Type III Hardcoat Anodized Black
Barrel Length & Material	10.5 Inch Profile, 4150 Chrome Moly Vanadium Steel
Caliber	5.56 NATO (Compatible with .223 Remington)
Twist Rate	1:7 Twist
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
Handguard	9" Free-Float M-LOK Rail, Slim Profile, Machined from 6061-T6 Aluminum
Manufacturing Origin	100% Made in the USA with Pro2A Tactical Lifetime Factory Warranty

Who Chooses This Upper Receiver?

Tactical & Close Quarters Marksmen

Operators looking for a fast-handling platform select the 10.5-inch barrel length. It offers an excellent balance between structural compactness in tight quarters and sufficient muzzle velocity for reliable downrange impact.

Bulky Optics & Thermal Users

Shooters running large scopes, heavy night-vision gear, or thermal sights choose a side charger because traditional rear charging handles are often blocked or difficult to pull beneath oversized optical frames.

AR Pistol & SBR Custom Builders

Custom builders looking to assemble a reliable close-quarters firearm prefer this drop-in assembly. It bypasses the hassle of tuning raw side-charging components at home and includes a lifetime factory guarantee.