5" 5.56 NATO Micro ARP Gold Spitfire Upper Assembly – 4" M-LOK

5" 5.56 Upper: Specs & Features

Stand out with the Moriarti Micro ARP AR-15 5.56 NATO 5" Complete Upper Assembly, featuring an eye-catching Gold Spitfire QD Blast muzzle device and premium components engineered for ultra-compact AR pistol builds. Designed for shooters who demand reliability, lightweight performance, and distinctive styling, this ARP upper delivers exceptional performance in a compact package.

Built around a 5-inch 4150 Chrome Moly Vanadium barrel with a 1:5 twist, this Micro ARP upper is equipped with a micro gas system, 4-inch slim-profile free-float M-LOK handguard, and 1/2x28 threaded muzzle for compatibility with a variety of muzzle devices and suppressor mounting systems. The Gold Spitfire QD Blast enhances the appearance while directing muzzle blast forward for a more comfortable shooting experience.
Compatible with mil-spec AR-15 lower receivers, this upper is ideal for building a mini ARP, upgrading an existing micro AR pistol, or creating a one-of-a-kind custom AR platform.

Bolt Carrier Group and Charging Handle are sold separately.

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Specifications

• Platform: AR-15 / Micro ARP

• Caliber: 5.56 NATO / .223 Rem

• Barrel Length: 5"

• Barrel Material: 4150 Chrome Moly Vanadium

• Barrel Finish: Black Nitride

• Twist Rate: 1:5

• Gas System: Micro

• Gas Block: .750 Low Profile Steel, Nitride

• Handguard: 4" Slim Free-Float M-LOK

• Muzzle Device: Gold Spitfire QD Blast

• Muzzle Threads: 1/2x28

• BCG: Not Included

• Charging Handle: Not Included

• Compatibility: Mil-Spec AR-15 Lower Receivers

• Upper Receiver: 7075-T6 aluminum

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Shop Related Categories

• Micro ARP Collection

• Silencers

• Gold AR-15 Collection

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Product Image Notice

Images may not be the exact representation of the product.

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Can I install this 5-inch upper on any Mil-Spec AR-15 lower?

Yes. This 5.56 NATO complete upper assembly is designed to fit virtually any Mil-Spec AR-15 lower receivers. Before installation, verify that your lower receiver and all associated components are compatible with your intended build and comply with all applicable laws.

FAQ

Will this upper fit my AR-15 lower?

Yes. It fits any standard mil-spec AR-15 lower receiver and uses a standard 5.56 bolt carrier group and STANAG/AR-15 magazines.

Can I shoot both 5.56 NATO and .223 Remington?

Yes. A 5.56 NATO or .223 Wylde chamber safely fires both 5.56 NATO and .223 Remington ammunition.

Is a bolt carrier group included?

No. The bolt carrier group is sold separately; any standard 5.56 AR-15 BCG will work.

What twist rate does it use?

A fast 1:5 twist, chosen to stabilize bullets from a very short barrel.

Related: 5.56 NATO & .223 Wylde AR-15 uppers