Pro2A 20" 6mm ARC Rifle Length Melonite M-LOK AR-15 Upper Kit

PRO2A 20" 6mm ARC 1/7.5 Rifle Length Melonite M-LOK AR-15 Upper Kit

Description

The Pro2A Tactical 20-inch 6mm ARC Complete Upper Kit includes everything required to convert a standard stripped lower receiver into a fully functional precision rifle system. Hand-assembled and quality checked in Georgia, this system pairs a velocity-maximizing 20-inch barrel with a smooth-cycling rifle-length gas system, a complete premium lower parts kit, and a full buffer tube setup with an adjustable stock. It provides long-range hunters and target shooters with a highly accurate, flat-shooting drop-in solution.

Key Features

All-In-One Build Solution: Includes a fully assembled complete upper receiver group, lower parts kit (LPK), fire control group, and all buffer/stock components needed to complete your rifle build.
6mm ARC Performance: Harnesses the advanced ballistics of the 6mm Advanced Rifle Cartridge, providing flat trajectories and low wind drift that rivals larger short-action cartridges out of a standard AR-15 frame.
Fast 1/7.5 Twist Rate: Optimized to stabilize heavier, high-ballistic coefficient (BC) match and modern hunting projectiles perfectly for tight downrange groupings.
Rifle-Length Gas Tuning: Minimizes felt recoil and cycling velocity by introducing a smooth, extended pressure curve ideal for long-range strings of fire.

Technical Specifications

Upper Receiver	Milspec Forged 7075-T6 Aluminum M4 Flat Top Receiver, Forward Assist & Dust Cover, M4 Feed Ramps (Type III Hardcoat Anodized)
Barrel Length & Profile	20-Inch Medium Profile
Caliber	6mm ARC (Advanced Rifle Cartridge)
Twist Rate	1:7.5 Twist
Barrel Material	4150 Chrome Moly Vanadium Steel with Premium Corrosion-Resistant Melonite Finish
Gas System Length	Rifle Length Direct Impingement with 0.750 Low-Profile Gas Block
Bolt Carrier Group	Milspec M16 Full Auto Profile, 8620 Steel Carrier, 9310 Bolt, Nitride Treated, MPI Tested
Charging Handle	Standard Milspec Charging Handle
Handguard	15 Inch Free Float Slim Profile M-LOK Rail System with Integrated Top Picatinny Rail
Muzzle Thread & Device	5/8x24 Thread Pitch with Standard A2 Flash Hider
Lower Parts Kit	Complete AR-15 LPK with Pins, Springs, Detents, Grip, and Polished Mil-Spec Fire Control Group
Stock Assembly	Mil-Spec 6-Position Buffer Tube Assembly, Carbine Buffer, Spring, Castle Nut, Endplate, and Adjustable M4 Stock

Why Choose This Product?

Bridging the gap between the portable AR-15 layout and true long-range capabilities requires proper mechanical tolerance matching across the entire rifle assembly. The Pro2A 20" 6mm ARC Upper Kit takes the guesswork out of building by providing component compliance right from the factory, combining a perfectly headspaced barrel and bolt system with a premium, reliable lower build kit. The rugged Melonite barrel treatment ensures exceptional bore life, easy cleaning, and extreme environmental resistance. If you need maximum downrange performance without upgrading to a heavy AR-10 platform, this complete package is the ultimate drop-in transformation solution.

More Information