ABC RIFLE COMPANY AR-15 7.62x39mm 10in Quadrail Handguard Complete Pistol Upper Receiver w/BCG And Charging Handle Sniper Grey. 62x39mm upper is built around a rugged 7075-T6 mil-spec forged upper receiver and a 10in 6061-T6 ABC Rifle Co Picatinny quadrail handguard offering rock-solid mounting and classic styling. The 10.5in 4150 CMV barrel features a 1:9.5 twist and is paired with a carbine-length 9in stainless gas tube and .750 low-profile steel gas block for smooth cycling. A 5/8x24 aluminum radial port muzzle brake helps tame recoil. Inside is a full-auto rated 8620 nitride BCG with a 9310 7.62x39mm bolt and enhanced firing pin. Finished with mil-spec steel hardware and a forged charging handle for reliability. Specifications for ABC RIFLE COMPANY AR-15 7.62x39mm 10in Quadrail Handguard Complete Pistol Upper Receiver w/BCG And Charging Handle: Manufacturer: ABC RIFLE COMPANY Caliber: 7.62x39mm Barrel Length: 10.5 in Gas System Length: Carbine Length Barrel Twist Rate: 1-10 Threads per Inch: 5/8x24 Muzzle Device: A2 Flash Hider Handguard Length: 10 in Handguard Style: Quad Rail Gun Type: Rifle Gun Make: AR Platform Gun Model: AR-15 Gas Block Journal Size-Length: .750 in Bolt Carrier Group Included: MIL-SPEC Charging Handle Included: MIL-SPEC Package Contents: ABC RIFLE COMPANY AR-15 7.62x39mm 10in Quadrail Handguard Complete Pistol Upper Receiver w/BCG And Charging Handle What firearm models does the manufacturer say ABC RIFLE COMPANY AR-15 7.62x39mm 10in Quadrail Handguard Complete Pistol Upper Receiver w/BCG And Charging Handle is compatible with? The manufacturer suggests that ABC RIFLE COMPANY AR-15 7.62x39mm 10in Quadrail Handguard Complete Pistol Upper Receiver w/BCG And Charging Handle is compatible with AR-15ABC RIFLE COMPANY UA762-BR10-QR10-SG: AR-15 7.62x39mm 10in Quadrail Handguard Complete Pistol Upper Receiver w/BCG And Charging Handle Sniper Grey