Pro2A Tactical 12.5" 5.56 NATO Carbine Length Melonite M-LOK AR-15 Upper

Build a high-performance, compact firearm with the Pro2A Tactical 12.5" 5.56 NATO Carbine Length Melonite M-LOK Upper. Engineered to offer the perfect balance of close-quarters maneuverability and optimal bullet velocity, this premium upper receiver features a heavy-duty 12.5-inch Melonite barrel with a versatile 1:7 twist rate and a highly reliable carbine-length gas system. Outfitted with a slim, free-float M-LOK handguard, this upper provides an exceptionally rigid platform for your optics and tactical accessories. It is the ultimate choice for custom AR pistol or registered short-barreled rifle (SBR) home defense setups.

Key Features & Technical Specifications

• Caliber: 5.56 NATO (Safely shoots both 5.56x45mm NATO and .223 Remington ammunition)
• Barrel Length: 12.5 Inches (The ideal ballistic length for short setups)
• Gas System: Carbine-Length (Tuned for smooth cycling, low recoil, and optimal pressure dwell time)
• Barrel Twist Rate: 1:7 Twist (Perfectly stabilizes heavy-grain tactical and defensive projectiles)
• Barrel Profile: Medium Profile for best weight vs performance ratio
• Barrel Finish: 4150 Chrome moly vanadium with Premium Melonite treatment for maximum bore longevity, rust resistance, and easy cleaning
• Handguard: 10 inch Lightweight, Free-Float M-LOK rail system for modular accessory mounting
• Muzzle Thread: 1/2x28 TPI A2 Flash Hider and Crush Washer 
• Receiver Material: Hard coat anodized black Mil-Spec forged 7075-T6 aluminum upper receiver with M4 feed ramps - comes with ejection port cover and forward assist
• Platform Compatibility: Fits any standard mil-spec AR-15 lower receiver

Why Choose the Pro2A Tactical 12.5" 5.56 NATO Upper?

The 12.5-Inch Dynamic Ballistic Advantage

Many tactical operators prefer a 12.5-inch barrel length over shorter 10.5-inch alternatives because it delivers a massive boost in muzzle velocity and terminal performance. This extra length ensures your 5.56 NATO rounds fragment reliably at defensive distances while maintaining a compact, fast-handling footprint that shines in close quarters.

Melonite Advanced Surface Hardening

Built to withstand extreme high-volume firing schedules, our Melonite-finished barrel features an advanced liquid nitriding surface treatment. This QPQ process creates an incredibly slick, friction-reducing layer both inside the bore and on the exterior profile. You get better corrosion resistance than traditional chrome lining without sacrificing match-grade accuracy.

Modular Free-Float M-LOK Handguard

Isolate your barrel from external pressures to prevent point-of-impact shifts. The rigid, free-floating M-LOK handguard allows you to clamp down on barricades or use tight shooting slings without affecting your downrange accuracy. With a full-length top Picatinny rail and clear cutouts at 3, 6, and 9 o'clock, mounting tactical lights, lasers, and vertical grips is clean and fast.

Mil-Spec Quality You Can Rely On

Every component in this upper is machined from top-tier materials. The receiver itself is forged from robust 7075-T6 aluminum and features precision-machined M4 feed ramps to ensure flawless feeding and extraction right out of the box. Simply add your favorite Bolt Carrier Group (BCG), charging handle, and other options to complete the build.

Lifetime Warranty and Support:

*Click here to learn more about our warranty.