XTS Complete Upper Receiver w/o BCG w/ Ce Rail AR-15 .223/5.56 19.5in 10.5in Barrel Pistol 1-7 Twist 1/2x28 Thread M-LOK Bird Cage Black Nitride. 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. These XTS complete uppers do not include the Bolt Carrier Group. Specifications for XTS AR-15 10.5in .223/5.56 Complete Upper w/o BCG w/ Ce Rail: Manufacturer: XTS Caliber: .223 Remington Overall Length: 18.5 in Barrel Length: 10.5 in Barrel Profile: Government Gas System Length: Pistol 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: 9 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 w/o BCG w/ Ce Rail Anchor Harvey Upper Receiver 5.56 NATO Barrel Ejection Port Cover 9in M-LOK Free Float Flat Top Rail 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 w/o BCG w/ Ce Rail is compatible with? The manufacturer suggests that XTS AR-15 10.5in .223/5.56 Complete Upper w/o BCG w/ Ce Rail is compatible with AR-15XTS XTS-CU-10CE: Complete Upper Receiver w/o BCG w/ Ce Rail AR-15 .223/5.56 19.5in 10.5in Barrel Pistol Length 1-7 Twist 1/2x28 Thread M-LOK Handguard Bird Cage Black Nitride Finish