
Availability: In Stock
The Battle Arms Development Bad Workhorse 556 upper receiver in 16-inch is a solid, no-frills upper built for shooters who want to assemble their own AR platform exactly how they want it. You get a complete 16-inch 5.56 NATO upper with a forged 7075-T6 receiver and quality Rosco barrel, minus the bolt carrier group and charging handle—giving you full control over those critical internals and letting you pair this upper with the lower and components that match your mission. Whether you're building a versatile rifle for the range, hunting, or defensive use, this upper delivers the foundation without forcing expensive parts you don't want.
The 16-inch Rosco barrel is 4150 chrome-moly vanadium steel with a 1:7 twist rate and M4 extension, chambered in 5.56 NATO and paired with a carbine-length gas system—a proven setup that runs soft and reliable across most ammunition. The barrel wears a nitride finish and ships with a low-profile .750-inch gas block and A2 flash hider; threads are 1/2-28 for easy muzzle device swaps. The upper itself is forged, hard-coat anodized black, and features M4 feed ramp cuts for dependable feeding.
The 15-inch WORKHORSE M-LOK free-float rail gives you ample real estate for lights, lasers, and accessories while keeping the gun light and handy. At 24.5 inches overall, this is a compact, ergonomic setup without sacrificing sight radius or practical capacity. Everything is USA-made, and the modular design means you can tune every other component to your exact specs—stock, trigger, grip, BCG, and charging handle all your call.
| Caliber | 5.56 NATO |
| Barrel Length | 16 inches |
| Barrel Material | 4150 Chrome-Moly Vanadium Steel |
| Barrel Finish | Nitride |
| Twist Rate | 1:7 |
| Barrel Extension | M4 |
| Gas System | Carbine-length |
| Gas Block | Low-profile, .750-inch diameter |
| Muzzle Thread | 1/2-28 |
| Muzzle Device | A2 Flash Hider |
| Receiver Material | Forged 7075-T6 Aluminum |
| Receiver Type | M4 |
| Receiver Finish | Hard-coat Anodized Black |
| Handguard | WORKHORSE 15-inch M-LOK Free-Float Rail |
| Overall Length | 24.5 inches |
| Bolt Carrier Group | Not Included |
| Charging Handle | Not Included |
This upper comes without a bolt carrier group or charging handle, so you'll need to source both to make it fully functional. Everything else you need for the upper assembly is included—barrel, gas system, rail, and flash hider. You'll also need a lower receiver to have a complete rifle.
The 16-inch barrel uses an A2 profile with a carbine-length gas system, which is a time-tested, reliable setup for 5.56 NATO shooting across a wide range of ammunition.
Yes. The barrel is threaded 1/2-28, which is the standard AR-15 pattern, so you can easily remove the A2 flash hider and install a suppressor, compensator, brake, or other 1/2-28 muzzle device.
The upper features an M4 receiver type and M4 feed ramp cuts, which is the standard modern AR-15 pattern and will mate with any compatible lower receiver.


SKU: 121688769 • Width: 5.5in • Height: 4in • Depth: 30in • Weight: 4.44oz





Availability: In Stock
The Battle Arms Development Bad Workhorse 556 upper receiver in 16-inch is a solid, no-frills upper built for shooters who want to assemble their own AR platform exactly how they want it. You get a complete 16-inch 5.56 NATO upper with a forged 7075-T6 receiver and quality Rosco barrel, minus the bolt carrier group and charging handle—giving you full control over those critical internals and letting you pair this upper with the lower and components that match your mission. Whether you're building a versatile rifle for the range, hunting, or defensive use, this upper delivers the foundation without forcing expensive parts you don't want.
The 16-inch Rosco barrel is 4150 chrome-moly vanadium steel with a 1:7 twist rate and M4 extension, chambered in 5.56 NATO and paired with a carbine-length gas system—a proven setup that runs soft and reliable across most ammunition. The barrel wears a nitride finish and ships with a low-profile .750-inch gas block and A2 flash hider; threads are 1/2-28 for easy muzzle device swaps. The upper itself is forged, hard-coat anodized black, and features M4 feed ramp cuts for dependable feeding.
The 15-inch WORKHORSE M-LOK free-float rail gives you ample real estate for lights, lasers, and accessories while keeping the gun light and handy. At 24.5 inches overall, this is a compact, ergonomic setup without sacrificing sight radius or practical capacity. Everything is USA-made, and the modular design means you can tune every other component to your exact specs—stock, trigger, grip, BCG, and charging handle all your call.
| Caliber | 5.56 NATO |
| Barrel Length | 16 inches |
| Barrel Material | 4150 Chrome-Moly Vanadium Steel |
| Barrel Finish | Nitride |
| Twist Rate | 1:7 |
| Barrel Extension | M4 |
| Gas System | Carbine-length |
| Gas Block | Low-profile, .750-inch diameter |
| Muzzle Thread | 1/2-28 |
| Muzzle Device | A2 Flash Hider |
| Receiver Material | Forged 7075-T6 Aluminum |
| Receiver Type | M4 |
| Receiver Finish | Hard-coat Anodized Black |
| Handguard | WORKHORSE 15-inch M-LOK Free-Float Rail |
| Overall Length | 24.5 inches |
| Bolt Carrier Group | Not Included |
| Charging Handle | Not Included |
This upper comes without a bolt carrier group or charging handle, so you'll need to source both to make it fully functional. Everything else you need for the upper assembly is included—barrel, gas system, rail, and flash hider. You'll also need a lower receiver to have a complete rifle.
The 16-inch barrel uses an A2 profile with a carbine-length gas system, which is a time-tested, reliable setup for 5.56 NATO shooting across a wide range of ammunition.
Yes. The barrel is threaded 1/2-28, which is the standard AR-15 pattern, so you can easily remove the A2 flash hider and install a suppressor, compensator, brake, or other 1/2-28 muzzle device.
The upper features an M4 receiver type and M4 feed ramp cuts, which is the standard modern AR-15 pattern and will mate with any compatible lower receiver.
SKU: 121688769 • Width: 5.5in • Height: 4in • Depth: 30in • Weight: 4.44oz

