ARP 9MM 3" Micro Complete Upper – AR-9 Pistol Upper, M-LOK

9mm Micro Upper: Specs & Features

Experience maximum compactness with the Moriarti ARP 9MM 3" Micro Complete Upper Assembly. Designed for builders seeking an ultra-compact ARP (AR Pistol) platform, this complete upper features a 3-inch barrel, free-float M-LOK handguard, integrated flash can, and dependable blowback operation.

Ideal for custom AR-9 pistol builds, this upper is compatible with most mil-spec AR-15 lowers configured for 9mm and is engineered for reliable performance in an exceptionally compact package. Whether you're building a range toy, backpack firearm where lawful, or a unique custom AR platform, the Moriarti 3-inch ARP upper delivers premium quality in a minimal footprint.

Product Specs:

• 6061 Billet PCC Upper Receiver
• 4.2″ Mlok free floating rail
• 3″(OAL) 9MM barrel
  • 1:10 Twist
  • 4150 Steel
  • Nitride Coated
  • Chrome-moly lined
  • 1/2×36Threads
• Dimpled Flash Can
• This upper comes complete with a nitride coated 9mm bolt carrier group (BCG)  and a standard charging handle.

What is an ARP?

ARP is a commonly used abbreviation for AR Pistol. Unlike a traditional rifle, an ARP features a compact configuration built around a pistol-designated lower receiver, making it popular among enthusiasts looking for lightweight and highly maneuverable AR platforms.

If you’re building an AR-9 and need a reliable, lightweight upper assembly, this is a great choice. Images may not be the exact representation of the product, rails Mlok may vary based on stock availability. 

FAQ

Is a lower receiver included?

No. This is an upper assembly only; the lower receiver, magazine and sights are not included.

What lower does it fit?

A dedicated pistol-caliber AR lower, such as a Glock-pattern lower using 9mm Glock-style magazines. A standard AR-15 lower with 5.56 magazines will not feed it.

How does it operate?

It is a direct blowback system, so it has no gas tube. A heavy PCC buffer is used for reliable cycling.

Related: 9mm Micro ARP · all Micro ARP pistols and uppers