Markings are not visible through the ejection port.
Carrier is marked "BRT" with Logo on the top rear side.
CHROME Full Auto Bolt Carrier Group BCG for the AR Family of Weapons (AR15, M16, M4)
Carpenter 158 bolt is Shot Peened, HP tested / MP inspected and Chrome plated for enhanced service life.
The USGI full auto bolt carrier is Hard Chromed outside and inside.
The Mil-Spec gas key is full Chrome, secured with heavy splined fasteners (per mil-spec drawing) and properly staked to ensure reliable gas system performance.
Bolt is marked "MP".
100% made in USA to USGI M16 specifications.