NGRS Sporting Goods

These AR-15 barrels are manufactured from 4140 chrome-moly steel that is heat treated, stress relieved, and finished with a mil-spec phosphate. Other features include: preinstalled and pinned barrel extension and a 0.750" gas block diameter with the gas port pre-drilled. The polished chamber is 5.56x45mm NATO and the muzzle is crowned and threaded 1/2"-28.