Expo Arms Barreled AR9 Upper Receiver - 9mm - 5.5"

The Expo Arms Barreled AR9 Upper Receiver bolts onto any compatible 9mm lower to build a capable, affordable pistol-caliber carbine, pairing a 5.5" barrel with a 4" M-LOK handguard in a straightforward blowback configuration.

Features:

• 5.5" barrel chambered in 9mm
• Blowback operating system
• 1/2x36 threaded muzzle with flash hider
• 4" M-LOK compatible handguard
• Threaded to accept standard 9mm-pattern muzzle devices
• Bolt carrier group and charging handle not included

Because the blowback system doesn't rely on a gas system, this upper keeps things simple: no gas block, gas tube, or gas port to tune, just a heavier bolt carrier and recoil spring doing the work. Leaving the BCG and charging handle out lets you select 9mm-specific components to match your build and buffer system.

At 5.5", this is one of the shortest barrel lengths Expo Arms offers for the 9mm platform, making it a compact option for an AR-format pistol build where overall length matters most.

Because it ships without a BCG or charging handle, you can pick 9mm-specific components rated for blowback operation rather than being locked into whatever comes in a box.

Expo Arms builds mil-spec AR-15 components exclusively for Primary Arms, backed by a limited lifetime warranty against manufacturer defects.