PRO2A 16" 6mm ARC Mid Length Melonite M-LOK AR-15 Upper Kit | Pro2A Tactical

PRO2A 16" 6mm ARC 1/7.5 Mid Length Melonite M-LOK AR-15 Upper Kit

Product Overview

The PRO2A 16" 6mm ARC 1/7.5 Mid Length Melonite M-LOK AR-15 Upper Kit is the ultimate all-in-one assembly package engineered for long-range precision and tack-driving consistency. Chambered in the cutting-edge 6mm Advanced Rifle Cartridge (ARC), this comprehensive master builder package delivers low-recoil, match-grade terminal ballistics out of standard AR-15 lower dimensions. Built with a premium 16-inch 4150 CMV heavy-profile barrel, the upper assembly comes completely headspaced, alongside a type-matched M16 profile Nitride bolt carrier group, a full lower parts completion group, and a 6-position adjustable buttstock setup to finish your performance project right out of the box.

Key Features

All-Inclusive Master Conversion Build: Streamlines your rifle project by bundling a pre-assembled upper receiver, pre-headspaced BCG, complete internal lower hardware pins, and an adjustable stock assembly.
Precision 1/7.5 Twist Optimization: Explicitly land-groove engineered to rotationally stabilize high-coefficient heavy projectiles cleanly for superb long-range flight trajectories.
Soft Gas Impingement Tuning: Operates on a smooth Mid-Length gas system combined with a 0.750" low-profile gas block to eliminate excessive cyclic gas shock, reducing recoil and speeding up target recovery.
Inside-Out QPQ Melonite Hardening: High-performance liquid salt-bath nitride surface treatment preserves uniform bore concentricity against gas erosion and shields components against moisture corrosion.
Slimline Modularity Rail: Features an anodized free-float aluminum handguard with a continuous top Picatinny axis and matrixed M-LOK alignment to keep accessory mounting slick and lightweight.

Technical Specifications

Upper Receiver Base	Mil-Spec Forged 7075-T6 Aluminum, Precision Machined M4 Feed Ramps, Type III Hardcoat Anodized Black Finish
Bolt Carrier Group (BCG)	Full M16 Profile, Toughened 9310 Steel Bolt, Caliber-Matched 6mm ARC Type II Bolt Face, Slick Black Nitride Finish, MPI Tested, Properly Staked Gas Key
Barrel Length & Contour	16 Inches; Medium Contour Profile
Barrel Material	4150 Chrome Moly Vanadium (CMV) Steel
Twist Rate Profile	1:7.5 Twist (Optimized for heavier long-range projectiles)
Barrel Coating Finish	QPQ Melonite / Premium Black Nitride Exterior and Interior Lining for Corrosive Resistance
Gas Operating System	Mid-Length Gas System with 0.750" Low Profile Gas Block, Stainless Steel Gas Tube Layout
Muzzle Thread & Device	5/8x24 TPI (Thread Pitch); Equipped with Standard A2 Flash Hider
Handguard Rails Profile	12 Inch Slim Profile Free-Float Aluminum Handguard, Continuous Top Picatinny Rail Alignment, Modular M-LOK Attachment Slots
Lower Receiver Parts	Complete Mil-Spec Component Springs and Pins Hardware, Single-Stage Fire Control Trigger Group (Trigger, Hammer, Disconnector), and Standard A2 Pistol Grip
Buttstock Assembly setup	6-Position Adjustable M4 Buttstock, Mil-Spec Diameter Buffer Tube (Extension), 3oz Carbine Buffer, and High-Tensile Recoil Buffer Spring Assembly
Manufacturing Origin	100% Proudly Assembled and Quality Checked in the USA with Pro2A Tactical Lifetime Factory Warranty

Why Choose the PRO2A 6mm ARC Precision Upper Kit?

Maximizing the true performance capability of the 6mm Advanced Rifle Cartridge demands strict mechanical harmony from the barrel extension to the bolt lugs. Pro2A Tactical eliminates part-to-part manufacturer tolerance stacking by building a pre-tuned, performance-headspaced upper assembly on the bench. Our premium 4150 CMV heavy barrels are button-rifled at a tight 1/7.5 twist to spin modern high-BC match projectiles flawlessly into tight sub-MOA strings. By running a properly gas-tuned mid-length loop alongside a durable 9310 tool steel bolt and a matching lower completion bundle, this kit operates with superb cyclic harmony. Avoid internal gas timing issues or headspacing errors, and build a high-velocity precision asset you can rely on from day one.

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