The Battle Arms Development WORKHORSE Complete Upper (BAD part no. WH-UR10.5B-Y-15C) builds a forged 7075-T6 aluminum receiver and matching free-float M-LOK handguard around a 10.5-inch, 4150 chrome-moly barrel chambered in 5.56 NATO/.223 Remington. M-LOK slots run along the 3, 6, and 9 o’clock positions of the handguard, and a full-length Picatinny rail tops the assembly with Battle Arms Development’s signature notch cut matching the receiver. A 9310 steel bolt and 8620 black-nitride carrier are individually head-spaced to the barrel for dependable function and simple field cleaning. This upper ships without a lower receiver.

Key Specifications

• Chambered in 5.56 NATO/.223 Remington.
• Barrel cut to 10.5 inches.
• Receiver 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 receiver.
• Barrel machined from 4150 chrome-moly steel.
• Barrel finished in black nitride.
• Individually head-spaced bolt and barrel pairing.
• Matched with a 9310 steel bolt.
• 8620 steel carrier with a black nitride finish 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 handguard and rail does it use? A free-float M-LOK handguard with slots at 3, 6, and 9 o’clock, topped by a full-length Picatinny rail with a notch matching the receiver.

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. Contact our Lubbock, Texas gun shop with any configuration questions before it’s ready to ship.