Dark Storm Industries DS-15 Bolt Action 5.56x45mm NATO 16inch Upper Receiver 1-7 Twist Anodized Black. Finally the bolt action conversion kit is here. Live in a restricted state and want to convert your standard lower receiver into a bolt action? Here is your solution Dark Storm Industries sell it three ways. A full kit that includes the 13 in Typhoon handguard and 1 in 7 twist 5.56 barrel with no gas port drilled. The same kit minus the handguard so you can use one of your choosing. Lastly the bare bones kit where you supply the barrel bolt and handguard and we supply everything else. This kit comes with a non ported .750 gas block to cover your existing barrels gas port. Specifications for Dark Storm Industries DS-15 Bolt Action 5.56x45mm NATO 16inch Upper Receiver: Manufacturer: Dark Storm Industries Caliber: 5.56x45mm NATO Barrel Length: 16 in Barrel Profile: Straight Barrel Twist Rate: 1-7 Finish: Anodized Color: Black Fabric/Material: Aluminum Gas Block Journal Size-Diameter: .750 in Handguard Length: 13 in Gun Rail: M-LOK Barrel Material: Steel Charging Handle Included: No Magazine Included: No Package Contents: Dark Storm Industries DS-15 Bolt Action 5.56x45mm NATO 16inch Upper Receiver Dark Storm Industries DSI-UK5-TBL-16T5-BLK: DS-15 Bolt Action 5.56x45mm NATO 16inch Upper Receiver 1-7 Twist Anodized Black