AR 15 barrel made from 4140 chrome-moly steel, 14.5” M-4 barrel is mounted on aircraftquality aluminum upper. Barrels are plated evenly with tough parkerized finish. Comes fully assembled with forward assist, ejection port cover assembly, gas tube assembly and heat shielded hand guards. With the Bolt, Bolt carrier, and charging handle option added, This will be a fully operational upper. Now available in 1x9 or 1x7 twist rate.This AR-15 barreled upper is headspaced, and ready to mount to your lower receiver after installing the bolt carrier group, see options. Once you have an assembled lower with the parts installed and mount the upper, this is an operational firearm 5.56mm.