The Colt 6930 Upper Assembly is used on the LE6930 and R0921CQB Commando model rifle. This upper receiver allows for a free-floated barrel while featuring a quad picatinny rail handguard and also features a gas-block mounted fixed front sight post with bayonet lug. The barrel is Colt's close quarter combat 10.3" chrome lined M4 barrel with an A2 flash hider up front.