The Battle Arms Development WORKHORSE Complete Upper (BAD part no. WH-UR10.5B-Y-15) pairs a forged 7075-T6 aluminum receiver with a matching free-float M-LOK handguard and a 10.5-inch, 4150 chrome-moly barrel chambered in 5.56 NATO/.223 Remington. The handguard carries M-LOK slots at the 3, 6, and 9 o’clock positions, while a full-length Picatinny rail runs across the top with Battle Arms Development’s signature notch cut to match the upper receiver. The barrel is individually head-spaced to a matching 9310 steel bolt and 8620 black-nitride carrier for reliable function and easy cleaning. Sold as an upper only with no lower receiver included, it’s built for shooters assembling a compact, pistol-length configuration.

Key Specifications

• Chambered in 5.56 NATO/.223 Remington.
• Barrel cut to 10.5 inches.
• Forged from 7075-T6 aircraft-grade aluminum.
• Free-float handguard with M-LOK slots at 3, 6, and 9 o’clock.
• Full-length Picatinny top rail with a signature notch matching the upper receiver.
• Barrel machined from 4150 chrome-moly steel.
• Barrel finished in black nitride for durability.
• Individually head-spaced to the included bolt for reliable function.
• Matched with a 9310 steel bolt.
• Carrier machined from 8620 steel and finished in black nitride for easy cleaning.

Frequently Asked Questions

Does this include a lower receiver? No, it’s sold as a complete upper only; you’ll need your own compatible lower to build a complete rifle or pistol.

What is the upper receiver made from? Forged 7075-T6 aircraft-grade aluminum, paired with a matching free-float M-LOK handguard.

What’s included with the barrel? A matched 9310 steel bolt and 8620 black-nitride carrier, individually head-spaced to that specific barrel for reliable function.

Buy the Battle Arms Development WORKHORSE Complete Upper

Order this Battle Arms Development upper from our AR15 uppers selection to build a rugged, reliable 5.56 platform. It ships from our Lubbock, Texas gun shop as soon as it’s ready.