AR-10mm 16" Slick Side M-LOK Complete Upper Receiver with LRBHO, BCG & Charging Handle

AR-10mm 16" Upper: Specs

The AR-10MM 16" Slick Side Complete Upper with Last Round Bolt Hold Open (LRBHO) is engineered for superior performance in your AR-style 10mm build. Crafted from billet 7075-T6 aluminum, this upper features a match-grade barrel, a slim M-LOK free-float handguard, and a fully assembled bolt carrier group and charging handle—all precision machined and assembled in the USA by Moriarti Arms.

Upper Features:

• Barrel: 16" 10MM match-grade barrel, 4150 CrMo steel, black nitride finish, 1:16 twist, 9/16x24 threaded with A2 flash hider

• Upper Receiver: Slick side billet receiver, 7075-T6 aluminum, Type III hardcoat anodized, LRBHO-enabled

• Handguard: Rifle-length slim M-LOK free-floating rail, aircraft-grade aluminum, black anodized finish

• Bolt Carrier Group (BCG): Ramped, compatible with Glock and Colt lowers, 8620 steel, mag phosphate finish

• Charging Handle: Standard mil-spec AR-15

• Gas System: Blowback

• Compatibility: Designed for use with most 10mm/.40 S&W AR-15 lower receivers

• Assembly: Fully assembled and function tested

• Origin: Made in the USA

• Lead Time: Estimated shipping in 6–8 weeks

Looking for a compact option? Check out the Moriarti AR-10MM 8.5" Slick Side M-LOK Complete Upper Receiver w/ LRBHO.

 Images may not be an exact representation of the product.

FAQ

What lower does it fit?

A dedicated pistol-caliber AR lower that takes Glock-style 10mm 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.

Is a lower receiver included?

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

Related: AR-10mm upper assemblies · pistol caliber carbines