DPMS Kitty Kat C7 .300 AAC Blackout 7.5 inch Upper Receiver One Size. The nitrided barrel is finished off with a 4in knurled tube free-float handguard R-marked front sight gas block and an A2 flash hider. Upper: Forged 7075-T6 C7 AR upper is machined to MIL-SPECS and hard coat anodized. Uppers include forward assist dust cover and A1 rear sight appature. Bolt Carrier Group: Shot-peened mil-spec Carpenter 158 steel bolt. Gas Key Hardened to USGI Specifications fastened with Grade 8 screws and Staked Per Mil-Spec. Carrier is 8620 steel M-16 full auto profile and is chrome lined and phosphate coated. Specifications for DPMS Kitty Kat C7 .300 AAC Blackout 7.5 inch Upper Receiver: Manufacturer: DPMS Caliber: .300 AAC Blackout Barrel Length: 7.5 in Gas System Length: Pistol Length Barrel Twist Rate: 1-7 Finish: Hardcoat Anodized Fabric/Material: 7075 T6 Aluminum Handguard Length: 4 in Barrel Material: Chrome Moly Vanadium Package Contents: DPMS Kitty Kat C7 .300 AAC Blackout 7.5 inch Upper Receiver DPMS DP51655189388: Kitty Kat C7 .300 AAC Blackout 7.5 inch Upper Receiver One Size