Moriarti AR-9 9mm 8.3" Side Charging Upper Assembly, BCG, LRBHO, M-LOK

AR-9 Side Charging Upper: Specs

The Moriarti AR-9 8.3" Side Charging Pistol Upper Assembly is engineered for performance, reliability, and compact power. Built on a non-reciprocating side charging billet upper receiver and integrated Last Round Bolt Hold Open (LRBHO) system, this upper is ideal for Glock-mag compatible builds and ready for action.

Perfect for custom AR-9 pistol builds, this upper delivers a clean cycling experience thanks to its blowback operation, a match-grade 8.3” 9MM barrel, and a 7.5” slim M-LOK handguard for lightweight modularity.

Each upper comes fully assembled and test-fired, ensuring flawless fitment and function for your next PDW or tactical pistol setup. Rails may vary slightly depending on stock availability, with no compromise on quality.

Key Specifications:

• Caliber: 9MM

• Barrel: 8.3", 4150 CMV, black nitride, straight profile, 1:10 twist

• Thread Pitch: 1/2x36 TPI

• Muzzle Device: A2 Flash Hider

• Gas System: Blowback

• Upper Receiver: 6061 billet aluminum, non-reciprocating side charging, Mil-Spec anodized, rear dust cover trap door

• LRBHO: Integrated Last Round Bolt Hold Open

• Handguard: 7.5" Slim M-LOK free-float, aircraft-grade aluminum

• Bolt Carrier Group: 8620 Steel, mag phosphate finish, M-16 cut, Glock & Colt compatible

• Compatibility: Glock mag AR-9, MA-9 lowers

• Charging Handle: Side charging (included)

• Assembly: Fully assembled and test-fired

• Complete the build with a Moriarti MA-9 Glock Mag Billet Lower Receiver

FAQ

What lower does it fit?

A dedicated pistol-caliber AR lower that takes Glock-style 9mm magazines. A standard AR-15 lower with 5.56 magazines will not feed it.

How does it operate?

It is a direct blowback pistol-caliber design with no gas tube or gas block, so a heavy PCC buffer is used for reliable cycling.

Does it have last round bolt hold open?

Yes. It has LRBHO, so the bolt locks back after the last round when used with an LRBHO-compatible lower.

What is a non-reciprocating side charger?

The charging handle is on the side of the upper and does not move while firing, so you can charge it without breaking your grip.

Is a lower receiver included?

No. This is an upper assembly only; the lower receiver and magazine are sold separately.

Related: AR-9 upper assemblies · pistol caliber carbines

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