PART NUMBER 14045 WEIGHT 6 lbs. 5 oz. (unloaded) CALIBER Chambered in .223/5.56 x 45 mm NATO UPPER RECEIVER CORE15® Mil-Spec Forged 7075-T6 M-4 Upper Receiver, Type III Class II Hardcoat anodized finish, M4 Feed Ramps, (1913 Picatinny rail flat top) with
