Build a compact 5.56 NATO platform with the BATTLEARMS WORKHORSE® 10.5-inch upper. Featuring a Rosco Manufacturing 4150 chrome-moly vanadium barrel, a 1:7 twist rate, and a 9.5-inch WORKHORSE® M-LOK® free-float rail, this complete upper assembly pairs dependable materials with practical, streamlined design. The BCG and charging handle are not included.
The forged 7075-T6 M4 upper receiver is hard-coat anodized black and made in the USA, with M4 feed ramp cuts. A low-profile .750-inch gas block and A2 flash hider complete the compact configuration, while the free-float handguard provides M-LOK® attachment points for compatible accessories. The barrel is nitride finished, chambered in 5.56 NATO, and fitted with an M4 barrel extension.
- 10.5-inch 4150 chrome-moly vanadium barrel with A2 profile
- 5.56 NATO chamber and 1:7 twist rate
- Nitride barrel finish; not chrome lined
- M4 barrel extension and 1/2-28 muzzle threads
- Low-profile gas block with .750-inch diameter
- WORKHORSE® 9.5-inch M-LOK® free-float rail
- Forged 7075-T6 M4 upper receiver with M4 feed ramps
- A2 flash hider included
- BCG and charging handle not included
- Overall length: 18.5 inches
- SKU: WH-UR-10.5-556
Choose this BATTLEARMS WORKHORSE upper for a compact, feature-rich foundation with recognized components and a clean M-LOK® profile. Verify compatibility with your intended build and follow all applicable laws and safe handling practices.
