Battle Arms Development Workhorse 10.5in 5.56 Nato Upper Receiver Assembly No Bcg No Ch WH-UR-10.5-556. 5in 4150V Chrome Moly Vanadium steel barrel chambered in 5.56 NATO with a 1:7 twist M4 barrel extension and a Mid-length gas system. The barrel...
Battle Arms Development Workhorse 10.5in 5.56 Nato Upper Receiver Assembly No Bcg No Ch WH-UR-10.5-556. 5in 4150V Chrome Moly Vanadium steel barrel chambered in 5.56 NATO with a 1:7 twist M4 barrel extension and a Mid-length gas system. The barrel...