Moriarti AR-15 .338 ARC 12.5" Upper Assembly with M-LOK and Thread Protector

AR-15 Line

Moriarti AR-15 .338 ARC 12.5" Upper Assembly | M-LOK | Thread Protector

The Moriarti AR-15 .338 ARC 12.5" Upper Assembly delivers the perfect balance of compact maneuverability and ballistic capability for suppressed or short-range applications. Built on a rugged A3 flat-top receiver, this upper assembly is chambered in the hard-hitting .338 Advanced Rifle Cartridge, optimized for superior accuracy, versatility, and modularity.

Key Features:

Barrel

• Length: 12.5"

• Chamber: .338 ARC

• Twist Rate: 1:5 (ideal for stabilizing heavy 200–225 grain bullets)

• Material: 4150 Chrome Moly Vanadium

• Finish: Nitride

• Thread: 5/8x24

• Muzzle Device: Thread Protector – ideal for custom muzzle devices or suppressed builds

• Profile: Government

Gas System

• Pistol-length for optimal cycling

• Steel low-profile gas block

Upper Receiver

• A3 flat-top, forged 7075-T6 aluminum

• Mil-spec hardcoat anodized

• Includes forward assist and dust cover

• Excellent platform for red dots, LPVOs, and night vision

Handguard

• 10" Super Slim Free Float M-LOK

• Lightweight aircraft-grade aluminum

• M-LOK attachment slots at 3, 6, and 9 o’clock

• Ergonomic, ventilated design for heat dissipation and control

Ballistic Performance Estimate (Supersonic Loads)

Suggested Pairings

• Customize further with Moriarti Builder Sets in Cerakote

Note: Bolt Carrier Group and Charging Handle not included but can be added as options.

Proudly made in the USA by Moriarti Armaments. The product images are for illustrative purposes, and the actual product may vary slightly in rail design or appearance, based on stock availability.