MANUFACTURER: FN FAMILY: Accessories MODEL: AR-15 Button Rifled Barrel TYPE: Accessory-Barrels ITEM GROUP: Rifle Accessories CALIBER/GAUGE: 223 Rem | 5.56 NATO FINISH: Manganese Phosphate FINISH TYPE: Applied Finish BARREL: 16" RATE-OF-TWIST: 1 in 7" RH Twist THREAD PATTERN: 1/2x28 SHIPPING WEIGHT: 2.05 lbs. ADDL INFO: Chrome Lined Chamber and Bore ADDL INFO: M4 Style Feed Ramps MFG MODEL NO: 20-100041 UPC: 845737008475