DPMS M-lok Nitride .308 Winchester 16 inch Upper Receiver w/BCG/CH One Size. 308 upper is here. This model offers a black nitride gas tube to better resist high heat and corrosion while maintaining a glossy black finish. All DP10 models come with a dimpled barrel for ease of gas block replacement if you choose to do so. We have also included a newly designed click switch position adjustable gas block so you can specifically tune to your load. Barrel: The dimpled nitride 308 WIN 1/10 twist mid-length gas system upper is paired with a Panther Arms 15in M-Lok free-float partial picatinny rail low profile adjustable click detent 3 position gas block and an A2-style muzzle device. The gas system is enhanced with a nitrided gas tube in order to better resist high heat and corrosion. Upper: Precision machined from forged 7075-T6 aluminum then Black anodize hard coated to MIL-8625 Type 3 class 2. With enhanced dual retention anti-slip and anti-rotating handguards. Bolt Carrier Group: Tool craft 9310 steel bolt assembly with extra strength extractor springs that is nitride for increased durability. 8620 carrier nitride treated with a nitride treated gas key properly staked with grade 8 fasteners. A 7075 T6 aluminum charging handle is also included. Specifications for DPMS M-lok Nitride .308 Winchester 16 inch Upper Receiver w/BCG/CH: Manufacturer: DPMS Caliber: .308 Winchester Barrel Length: 16 in Barrel Profile: A2 Gas System Length: Mid Length Barrel Twist Rate: 1-10 Threads per Inch: 5/8x24 Gas Block Journal Size-Diameter: .750 in Handguard Length: 15 in Bolt Carrier Group Included: MIL-SPEC Charging Handle Included: MIL-SPEC Package Contents: DPMS M-lok Nitride .308 Winchester 16 inch Upper Receiver w/BCG/CH DPMS DP51655135005: M-lok Nitride .308 Winchester 16 inch Upper Receiver w/BCG/CH One Size