8.5" barrel, 4140 Steel, button rifled, 1-9" twist, 5.56mm. Included is the barrel, barrel extension and barrel extension pin .750" at the gas block, .610" diameter at the smallest. Uses an 8" gas tube which you can get here:
Or you can simply cut down a standard carbine gas tube to 8" long.
This product was added to our catalog on Saturday 19 January, 2008.