PRO2A 12.5" 300 Blackout Pistol Length Melonite AR-15 Upper Kit

PRO2A 12.5" 300 Blackout 1/8 Pistol Length Melonite AR-15 Upper Kit

Build a hard-hitting, perfectly balanced firearm configuration with the PRO2A 12.5" 300 Blackout Pistol Length Melonite M-LOK Upper Kit. This 100% American-made master conversion package includes every core internal and external hardware component required to turn a standard stripped lower receiver into a highly reliable AR pistol or short-barreled rifle (SBR). Optimized to capture excellent velocity from the 300 AAC Blackout cartridge while maintaining close-quarters maneuverability, this optics-ready kit pairs a precision-hardened 4150 CMV steel barrel with a mil-spec forged upper. It ships completely assembled with a matching pre-headspaced M16 bolt carrier group, a full mil-spec lower parts kit (LPK), and a premium pistol buffer tube extension assembly.

Key Features

All-In-One Master Rifle Package: Eliminates tracking down separate components by packaging the complete upper assembly, pre-headspaced BCG, lower internal hardware springs/pins, and receiver extension buffer setup together.
Optimized 12.5-Inch Ballistic Profile: Provides increased velocity and enhanced gas dwell time compared to ultra-short configurations, squeezing maximum terminal performance out of the 300 BLK cartridge.
Advanced Melonite Barrel Protection: The heavy-duty 4150 CMV steel barrel is fully treated with an advanced Salt Bath Melonite finish inside the bore and across the exterior to extend operational service life and maximize corrosion resistance.
Versatile 1:8 Twist Rate: Precision button-rifled twist configuration engineered specifically to stabilize standard mid-grain supersonic rounds as well as heavy duty subsonic ammunition perfectly.
Reliable Pistol-Length Gas Dynamics: Precision engineered to provide consistent internal cycling pressures across a wide spectrum of grain weights, cleanly cycling fast supersonic ammunition up to heavy suppressed loads.
Slim Profile Free-Float M-LOK Rail: Machined from high-strength aluminum, the lightweight handguard isolates barrel vibrations to preserve uniform mechanical accuracy while providing a continuous top rail and modular M-LOK spacing.

Technical Specifications

Upper Receiver Assembly	Mil-Spec Forged 7075-T6 Aluminum, M4 Feed Ramps, Forward Assist & Port Cover, Type III Hardcoat Anodized Black Finish
Bolt Carrier Group	Full M16 Profile, Heavy-Duty 9310 Steel Bolt Face, Nitride/Melonite Treatment, Properly Staked Gas Key, MPI Tested
Charging Handle	Standard Mil-Spec Charging Handle Assembly
Barrel Length & Steel	12.5 Inch Profile, 4150 Chrome Moly Vanadium Steel, Medium Contour, Melonite Treated Interior & Exterior Bore
Caliber	300 AAC Blackout (7.62x35mm)
Twist Rate	1:8 Twist
Gas Operating Block	Pistol-Length Gas System, Low-Profile Gas Block Machined from 4140 Steel, Stainless Steel Gas Tube
Muzzle Device Component	Standard A2 Flash Hider with Crush Washer Pre-Installed, 5/8x24 Thread Pitch
Handguard Rail	10 Inch Slim Profile Free-Float Aluminum Handguard, Continuous Top Picatinny Alignment, Modular M-LOK Attachment Points
Lower Receiver Parts Kit	Complete Mil-Spec Spring and Pin Kit, Polished Single-Stage Hammer and Trigger Assembly, Standard A2 Pistol Grip
Pistol Brace	Standard Blade, AR-15 Pistol Buffer Tube, Standard 3oz Carbine Buffer, and High-Tensile Buffer Spring
Manufacturing Origin	100% Assembled and Quality Checked in the USA with Pro2A Tactical Lifetime Factory Warranty

Why Buy This Product?

The PRO2A 12.5" 300 Blackout Pistol Length Melonite Upper Kit directly hits the ballistic "sweet spot" for intermediate defensive calibers. While ultra-short barrels maximize concealment, they often clip muzzle velocities and limit downrange terminal impact. Moving to a 12.5-inch barrel configuration grants the 300 Blackout cartridge the extra runway required to extract full velocity potential from supersonic hunting loads, while expanding the internal gas dwell time for significantly smoother cycling window dynamics when transitioning to suppressed, subsonic ammunition configurations.

Sourcing parts from different brands frequently introduces slight tolerance errors, which often lead to frustrating mechanical issues such as weak extractions, short-cycling, or light primer strikes on the range. Pro2A Tactical eliminates this headache by designing a cohesive, factory-matched master bundle where the gas block port size, buffer spring tension, and pre-headspaced M16 bolt carrier group work together under balanced internal cycle speeds right out of the box. Protected by a complete factory lifetime warranty and built using strictly domestic components, this master bundle delivers unmatched tactical power without the technical guesswork.

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