PRO2A 18" .458 Socom 1/14 Carbine Length Melonite M-LOK AR-15 Upper Kit

Product Overview

The PRO2A 18" .458 Socom 1/14 Carbine Length Melonite M-LOK AR-15 Upper Kit delivers unparalleled big-bore ballistics and extended range potential within the standard, lightweight AR-15 footprint. Built around an 18-inch 4150 CMV steel barrel treated with a rugged Melonite finish, this complete conversion package maximizes velocity and terminal energy for the hard-hitting .458 SOCOM cartridge. Outfitted with a carbine-length gas system to balance heavy cyclic pressures and an independent free-float M-LOK rail system for optimal barrel harmonics, this range-ready bundle includes a specialized big-bore bolt carrier group, full lower parts kit, and adjustable stock assembly to drop directly onto your choice of mil-spec lower receivers.

Key Features

Maximized Big-Bore Velocity: The 18-inch barrel length fully extracts the powder-burn efficiency of heavy big-bore rounds, making it an elite choice for large game and deep-woods hunting.
Rugged Melonite Barrel Armor: Liquid QPQ Nitride treatment yields an exceptionally hard, low-friction bore and exterior surface for extended barrel longevity and superior element resilience.
Optimal 1/14 Twist Rate: Engineered specifically to stabilize heavy-grain projectiles uniformly, ensuring consistent trajectories with the caliber's most popular hunting and defensive loads.
Enlarged Ejection Port Receiver: Features a premium upper receiver with a factory-modified, enlarged ejection port designed to facilitate flawless feeding and case extraction sequences.
All-In-One Conversion Kit: Ships fully bundled with a matching .458 SOCOM Bolt Carrier Group (BCG), slim free-float M-LOK handguard, complete lower build components tree, and stock assembly hardware.

Technical Specifications

Caliber / Chamber:	.458 SOCOM
Barrel Length:	18 Inches
Barrel Material:	4150 Chrome Moly Vanadium Steel
Twist Rate:	1:14 Right-Hand Twist Button Rifled
Barrel Coating Finish:	QPQ Melonite / Black Nitride Finish
Gas System Length:	Carbine-Length Gas System with 0.750" Low Profile Gas Block Layout
Upper Receiver Type:	7075-T6 Forged Aluminum with Enlarged Ejection Port, Forward Assist & Dust Cover (Type III Hardcoat Anodized)
Bolt Carrier Group (BCG):	Premium M16 Profile BCG with Properly Hooked .458 SOCOM Bolt Face, Nitride Finish, MPI Tested
Muzzle Threads & Device:	5/8x24 TPI; Premium Big-Bore A2 Flash Hider
Handguard Interface:	15 inch Free-Float Ergonomic Slim M-LOK Rail System with Continuous Top Picatinny Rail Layout
Lower Parts Kit (LPK):	Complete Mil-Spec Lower Parts Kit including crisp Single-Stage Fire Control Group (Trigger, Hammer, Springs), A2 Pistol Grip, and full pins/detent arrays
Stock Assembly:	6-Position Adjustable M4 Stock complete with Mil-Spec Buffer Tube, Heavy Recoil Buffer, Spring, Castle Nut, and End Plate
Manufacturing Origin:	100% Made in the USA

Why Choose This Product?

This comprehensive conversion kit provides modern builders with an elite intermediate-chassis solution that transitions seamlessly into a hard-hitting, big-bore platform with maximum velocity retention. By packaging a factory-modified, enlarged ejection port receiver with a specialized .458 bolt face group and a tuned carbine-length gas system, it completely eliminates cycling bottlenecks and ensures flawless extraction reliability with heavy hunting cartridges. Shipped complete with a robust Melonite-treated barrel and all required frame assembly pieces, this kit offers sub-MOA precision, maximum downrange terminal energy, and field-tested durability engineered for ultimate performance.