PRO2A 20" 350 Legend 1/16 Carbine Length Melonite M-LOK AR-15 Upper Kit

Product Description

Maximize the full ballistic performance, maximum muzzle velocity, and long-range accuracy of the 350 Legend straight-walled cartridge with the complete PRO2A 20" 350 Legend Carbine-Length AR-15 Upper Kit. This master build package provides a meticulously headspaced 20-inch barrel assembly paired with a reliable carbine gas track system optimized for proper dwell time with heavy straight-wall cartridge configurations. Engineered as an all-in-one building solution, this kit comes fully populated with a premium M16 profile bolt carrier group, a mil-spec charging handle, a complete lower parts kit, and a full carbine stock assembly—supplying every essential internal component required to finish your stripped lower receiver.

Key Features

All-Inclusive Master Build Kit: Bundles the complete barreled upper receiver with a premium bolt carrier group, charging handle, full lower parts kit, and rear receiver stock assembly.
Optimized Velocity Profile: 20-inch heavy duty barrel profile ensures full powder burn to capture maximum velocity, flat trajectories, and true match-grade terminal performance for hunting environments.
Straight-Wall Hunt Compliance: Specifically optimized for the 350 Legend cartridge, granting maximum lawful efficacy in states with restrictive straight-wall public land harvesting mandates.
QPQ Melonite Extreme Armor: Barrel bore, chamber, and exterior are fully liquid nitrocarburized to exceed mil-spec chrome lining in surface hardness, heat dissipation, and corrosion resistance.
Slim Profile M-LOK Workspace: Features a continuous top Picatinny rail interface seamlessly blended into a 15-inch free-floating M-LOK handguard for rigid mounting stability.

Technical Specifications

Caliber / Chambering	350 Legend (Straight-Walled Rifle Cartridge)
Barrel Length / Steel	20 Inches / 4150 Chrome Moly Vanadium (CMV) Steel
Barrel Finish & Profile	QPQ Melonite / Black Nitride (Internal & External) — Medium Profile
Twist Rate / Feed Ramps	1:16 Twist / Engineered Single-Large M4 Feed Ramp Profile for Reliable Straight-Wall Case Feeding
Gas System Mechanics	Carbine Length Direct Impingement with a 0.750" Low-Profile Steel Gas Block
Upper Receiver	Milspec 7075-T6 Forged Aluminum, Type III Hardcoat Anodized, Forward Assist & Dust Cover
Handguard System	12-Inch Ultra-Lightweight Free-Float 6061-T6 Aluminum M-LOK Rail
Muzzle Configuration	Standard A2 Flash Hider / 5/8x24 TPI Thread Pitch
Bolt Carrier Group (BCG)	M16 Profile Full-Auto Capable, Case Hardened 8620 Steel Carrier, 9310 Steel Bolt (MPI Tested), Advanced Nitride Finish
Charging Handle	Standard Mil-Spec AR-15 Charging Handle
Lower Parts Kit (LPK)	Complete AR-15 Lower Parts Kit (Standard Milspec ELG Trigger / Fire Control Group, Pistol Grip, Detents, Springs, Pins, and Safety Selector)
Stock & Buffer Assembly	6-Position Collapsible M4 Stock, Mil-Spec Diameter Buffer Tube, Carbine Recoil Buffer, and High-Tensile Buffer Spring
Manufacturing Origin	100% Designed, Machined, and Assembled in the United States
Warranty Protection	Backed by Pro2A Tactical's Structural Lifetime Warranty

Why Choose This Product?

The PRO2A 20" 350 Legend Carbine Length Build Kit removes the complexity of sourcing structural precision components across separate vendors by providing a perfectly headspaced and balanced ecosystem out of the box. Sourcing standalone components often creates headspacing risk or feeding failure with straight-walled cases. This system resolves that constraint out of the box, utilizing a single large M4 feed ramp configuration built explicitly to chamber straight-wall ammunition smoothly. Completely paired with an advanced M16 Nitride bolt group, lower frame parts, and stock hardware, this system ensures total hardware harmony under the protection of a full Structural Lifetime Warranty.

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