PRO2A LEFT HAND 16" 12.7x42 (50 Beowulf) 1/20 Carbine Length NR Side Charging M-LOK AR-15 Upper

Product Overview

The Pro2A Left Hand 16" 12.7x42 Carbine Length Upper Receiver delivers a premium big-bore upgrade engineered explicitly for southpaw shooters. Chambered in hard-hitting 12.7x42mm (fully compatible with .50 Beowulf ammunition loads), this assembled setup replaces traditional rear charging handle strains with a highly-efficient Non-Reciprocating (NR) Side Charging System. Built to perform flawlessly under intense straight-walled big-bore pressures, it provides unparalleled ergonomic handling and massive, flat-out stopping power.

Key Features

True Left-Hand Mirroring: Dedicated left-handed upper layout features a left-side ejection path to keep hot big-bore brass entirely out of the operator's line of sight.
Non-Reciprocating (NR) System: Dynamic side charging mechanism remains perfectly stationary during firing sequences, providing smooth manual manipulation even with oversized hunting optics mounted.
Enlarged Ejection Port: Widened opening is specifically machined to cleanly throw heavy 12.7x42 brass without dangerous cycle blockages or stovepiping.
Free-Float Handguard: Rigid aluminum rail ensures unhampered barrel harmonics and extensive structural layout space for standard tactical accessories.

Technical Specifications

Upper Receiver	Patented Gibbz Arms G4 Billet Aluminum Non-Reciprocating Side Charging Upper Receiver, Left Hand Ejection, Enlarged Big Bore Ejection Port, M4 Feed Ramps, Anodized Finish
Charging System	Right-Side Non-Reciprocating Charging System (Static Handle Design) for Left-Eject Configuration
Barrel Length & Profile	16-Inch Heavy Profile
Caliber	12.7x42mm (.50 Beowulf Compatible)
Twist Rate Matrix	1:20 Twist Rate
Barrel Material & Treatment	4150 Chrome Moly Vanadium Steel, Premium Corrosion-Resistant Melonite Finish
Gas Operating Block	Carbine Length Direct Impingement, Low-Profile Steel Gas Block, Stainless Steel Gas Tube
Muzzle Thread & Device	49/64x20 Thread Pitch, High-Efficiency Competition Muzzle Brake
Handguard Rail	15" Slim Free-Float M-LOK Handguard, Machined from 6061-T6 Aluminum with Top Picatinny Rail
Manufacturing Origin	100% Made in the USA with Pro2A Tactical Lifetime Factory Warranty

Who Chooses This Upper Receiver?

Left-Handed Big-Bore Hunters

Southpaw hunters targeting large game, hogs, or bears in thick brush select this dedicated setup. It keeps hot, massive .50-caliber empty casings out of their face and eyes while delivering devastating close-to-medium range terminal stopping power.

Tactical Southpaw Marksmen

Shooters wanting premium ergonomic manipulation rely on the non-reciprocating side-charging setup. Bypassing the awkward reach over a standard AR-15 rear charging handle allows left-handed operators to clear, charge, or check the chamber instantly without breaking their cheek weld.

AR-15 Builders Demanding Drop-In Power

Custom gunsmiths aiming to update a standard small-frame lower into an innovative, heavy-hitting utility weapon choose this complete upper. It snaps easily onto mil-spec AR-15 lowers, allowing standard modifications to instantly fire straight-walled .50-caliber loads.