PRO2A 8.5" .458 SOCOM 1/14 Pistol Length NR Side Charging Melonite M-LOK AR-15 Upper

Bring massive big-bore kinetic performance to a highly compact layout with the PRO2A 8.5" .458 SOCOM Non-Reciprocating (NR) Side Charging AR-15 Upper Receiver Assembly. Engineered from the ground up to conquer feeding and manual action bottlenecks, this complete premium upper drops directly onto any standard Mil-Spec AR-15 lower receiver. By moving the cocking mechanism to a stationary left-side charging handle, it eliminates structural interference with large rifle scopes, red dots, or thermal optics. Built around a premium 1/14 twist Melonite-treated barrel with an enlarged ejection port, it delivers relentless close-range stopping power with total physical authority.

Key Features

Non-Reciprocating Side Charging Action: The ergonomic left-side handle remains completely stationary while the weapon fires, protecting your support hand and clearing room for optics.
Enlarged Ejection Port Cutout: Specially widened receiver port ensures clean, reliable clearance of heavy .458 SOCOM brass casings, eliminating stovepipe cycling failures.
Advanced Melonite Barrel Treatment: The premium 4150 CMV steel barrel is fully treated with an advanced Salt Bath Melonite finish inside the bore and across the exterior to extend erosion service life and maximize corrosion resistance.
Hand-Polished Single Feed Ramp: Custom, widened single feed ramp geometry eliminates common friction and bullet nose drag associated with single-stack big-bore magazines.
Slim Profile Free-Float M-LOK Handguard: Machined from high-strength aluminum, the lightweight rail isolates barrel vibrations to preserve uniform mechanical accuracy while providing modular M-LOK attachment slots.

Technical Specifications

Upper Receiver Assembly	Gibbz Arms G4 Premium Non-Reciprocating Side Charging Upper Receiver, Billet Aluminum, Custom Enlarged Ejection Port, Type III Hardcoat Anodized Black Finish
Charging Handle	Left-Side Non-Reciprocating Charging Handle Assembly (Stationary During Firing Cycle)
Barrel	8.5 Inch Profile, 4150 Chrome Moly Vanadium (CMV) Steel, Medium Contour Profile, Melonite Treated Interior & Exterior Bore
Caliber	.458 SOCOM
Twist Rate	1:14 Twist
Gas Operating Block & System	Pistol-Length Gas System, Low-Profile Gas Block Machined from 4140 Steel, Stainless Steel Gas Tube
Muzzle Device Component	Standard 5/8x24 Thread Pitch, Enlarged to 45 Cal, A2 Flash Hider with Crush Washer Pre-Installed
Handguard Rail	7 Inch Slim Profile Free-Float Aluminum Handguard, Continuous Top Picatinny Alignment, Modular M-LOK Attachment Points
Manufacturing Origin	100% Assembled and Quality Checked in the USA with Pro2A Tactical Lifetime Factory Warranty

Why Buy This Product?

Short-barreled big-bore conversions on standard rear-charging AR receivers frequently trap home builders with awkward optic clearance and ejection failures. The PRO2A 8.5" .458 SOCOM Non-Reciprocating Side Charging Upper directly answers these vulnerabilities. By integrating a widened ejection port with a smooth left-side manual cocking mechanism, you gain a ruggedly dependable heavy-grain system that lets you clear or cycle the action without dropping your sight line or moving your hands out of ready position. Hand-assembled, properly headspaced, and quality-tested in the USA, this upper upgrade gives you immense close-quarters kinetic capability in a flat-shooting, ergonomic build.

More Information

More Information
SKU	P2ANR458AX7PIS85-TK
Barrel Length	8.5 inch
Rifle Caliber	458 Socom
Manufacturer	Pro2A Tactical

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