Noveske AR-15 Ejection Port Dust Cover 300 BLK

Noveske engraves this ejection port cover with 300 BLK on the outfacing side, which makes the chambering obvious at a glance. It fits standard mil-spec upper receivers.

The cover comes as a complete assembly with the port door rod, spring, and clip, so a stripped upper or a worn cover can be finished in one sitting. On a 300 BLK build the marking earns its keep beyond looks. Mixing a 300 BLK round into a 5.56 upper is a mistake nobody wants to make twice, and a marked port cover is one more chance to catch it before the round goes in.