KAK Industry Bolt Carrier Group Features The KAK Industry Bolt Carrier Group runs an M16 full auto carrier profile machined from 8620 steel and properly heat treated to the tolerances needed for reliable function in AR-15 and M16 pattern rifles. The 9310 steel bolt offers excellent strength and fatigue resistance compared to lower grade alternatives helping the bolt survive the repeated stress of high round count use. Chrome lining inside the carrier reduces friction during cycling which keeps the action running smoothly even when fouled from extended firing sessions. A phosphate finish over the carrier provides a corrosion resistant layer that works alongside the chrome lining to protect the most critical moving parts of the rifle. Supporting components are built to the same standard throughout including a single piece billet machined 4140 extractor with a phosphate coating for reliability and corrosion resistance a chrome plated 4340 cam pin and an 8740 chrome plated firing pin that is precision ground and heat treated. An S7 tool steel ejector and extractor retaining pin add further durability to parts that see constant wear. The 4130 machined billet steel gas key is chrome lined and chrome plated then precision staked with grade 8 properly heat treated carrier key screws to prevent loosening under recoil. For AR-15 and M16 owners who want a dependable well built bolt carrier group without the price of a full chrome unit KAK Industry delivers proven materials and construction at an accessible price point. KAK Industry Bolt Carrier Group Specifications Manufacturer: KAK Industry Model: Bolt Carrier Group Caliber: 5.56 NATO Compatible Hosts: AR-15 M16 Color: Black Material: Steel Carrier Type: M16 Finish: Phosphate Weight: 0.73 lbs Available At: GrabAGun