KAK Complete AR15 Upper Receiver – 9mm – 4″ Barrel – 2.9″ MLOK

UpperBarrel Length- 4″Barrel Material- 41V50 Button Rifled BarrelChamber 9MM NATOTwist Rate 1:10Muzzle Device Milspec A2 birdcage 1/2-36Gas System- Blowback Upper Receiver- Forged 7075 T6 Aluminum, Precision Machined to M16/M4 SpecHandguard- 2.9″, High Quality 6061 T6 Material Mlok with Proprietary Clamping System and Heavy-Duty Barrel Nut BCGOne piece BCGAuto Profile Carrier Machined from Aircraft/ Bearing Quality 8620 Steel, Properly Heat Treated, Ground to Perfection, BlackNitride Finish by H&MFiring pin is machined from 8740, precision ground, and chrome platedOne Piece Billet Fully Machined Enhanced Extractor, Phosphate coated for Increased reliability and corrosion resistanceS7 tool steel ejector and extractor retaining pin4130 Gas Key, nitride, precision staked using our hydraulic staking machineCarrier key screws- Grade 8, Properly Heat Treated and staked All KAK complete upper receivers are test fired for feed and function using commercially loaded ammunition