The WORKHORSE complete upper receiver is purpose-built around the forged WORKHORSE 7075-T6 aircraft-grade aluminum receiver and free-float rail handguard with M-LOK attachment point at 3, 6, and 9 o'clock positions. At 12 o'clock is a full-length Picatinny accessory rail with their signature notch cut matching the upper receiver. Every upper receiver is equipped with a 4150 chrome-moly steel black nitride barrel for durability and accuracy. The barrel is individually head-spaced with a matching 9310 steel bolt and 8620 black nitride carrier for ultimate reliability and ease of cleaning.