XTS Complete Upper Receiver w/o BCG AR-15 223/5.56 19.5in 10.5in Carbinel Government 1-7 Twist 1/2x28 Thread M-LOK Bird Cage Black Nitride Finish. 56 upper comes FULLY ASSEMBLED with a 5.56 NATO barrel capable of shooting both .223 and 5.56. With an Anchor Harvey Upper and an XTS Hand Guard this will make your next build the ultimate AR. Includes: ANCHOR HARVEY Upper Receiver. These XTS complete uppers do not include the Bolt Carrier Group. Specifications for XTS AR-15 10.5in 223/5.56 Complete Upper Receiver w/o BCG: Manufacturer: XTS Caliber: .223 Remington Overall Length: 18.5 in Barrel Length: 10.5 in Barrel Profile: Government Gas System Length: Carbine Length Barrel Twist Rate: 1-7 Threads per Inch: 1/2x28 Muzzle Device: A2 Flash Hider Finish: Nitride Color: Black Gun Model: AR-15 Condition: New Fabric/Material: Stainless Steel Gas Block Journal Size-Diameter: .750 in Handguard Length: 10 in Handguard Style: Round Rail Gun Rail: M-LOK Gun Make: AR Platform Barrel Material: 4150 Chrome Moly Vanadium Bolt Carrier Group Included: No Charging Handle Included: MIL-SPEC Weight: 19.3 oz Magazine Included: No Mount Type: M-LOK Country of Origin: USA Package Contents: XTS AR-15 10.5in 223/5.56 Complete Upper Receiver w/o BCG Anchor Harvey Upper Receiver 5.56 NATO BARREL 10.5in XTS Charging Handle XTS Forward Assist XTS Ejection Port Cover 10in M-LOK Black Gas Block Gas Tube Bird Cage Muzzle Brake What firearm models does the manufacturer say XTS AR-15 10.5in 223/5.56 Complete Upper Receiver w/o BCG is compatible with? The manufacturer says that XTS AR-15 10.5in 223/5.56 Complete Upper Receiver w/o BCG is compatible with AR-15XTS XTS-CU-10BK: Complete Upper Receiver w/o BCG AR-15 223/5.56 19.5in 10.5in Carbinel Length Government 1-7 Twist 1/2x28 Thread M-LOK Handguard Bird Cage Black Nitride Finish BLack