Moriarti AR-10MM 10.5" Slick Side Premium Complete Upper Receiver | LRBHO

Uppers

Moriarti AR-10MM 10.5" Slick Side Premium Complete Upper Receiver | LRBHO

The AR-10MM 10.5" Slick Side Premium Upper by Moriarti Arms is built for precision, performance, and rugged use in compact platforms. Featuring a Last Round Bolt Hold Open (LRBHO) function and a blowback operating system, this upper is ideal for those building a reliable and high-performance 10mm AR pistol or SBR setup.

The 10.5” match-grade barrel is crafted from 4150 chrome moly steel, finished with a durable black nitride coating. Chambered in 10MM Auto, it has a 1:16 twist and 9/16x24 threads, finished with a standard A2 flash hider. The billet slick side upper receiver is precision machined from certified 7075-T6 aluminum and black hardcoat anodized to military specs.

This complete upper also includes a slim, rifle-length M-LOK free-float rail, ideal for customization and enhanced barrel cooling. The included .40 S&W/10mm BCG is Glock and Colt style compatible, machined from US-made 8620 steel, and phosphate coated for durability.

Upper Features:

• Barrel: 10.5” 10MM Match Grade, 4150 CrMo Steel, Black Nitride Finish

• Twist Rate: 1:16

• Thread Pitch: 9/16x24 with A2 Flash Hider

• Gas System: Blowback

• Receiver: Billet 7075-T6 Aluminum, Slick Side Design, Black Hardcoat Anodized

• Handguard: 10" Lightweight Free-Float Rifle-Length M-LOK Rail

• Bolt Carrier Group: AR-40 .40 S&W/10MM, US-Made 8620 Steel, Phosphate Finish, Glock/Colt Compatible

• Charging Handle: Mil-Spec AR-15

• Compatibility: Works with Glock-style AR-45 lowers and standard AR-15 components

• LRBHO Feature: Last Round Bolt Hold Open

• Assembly: Fully Assembled and Tested

• Made in the USA by Moriarti Armaments

Note: This upper is part of Moriarti’s premium line and has a current ETA of 6–8 weeks. Product images may vary slightly due to design updates.