The CMMG Ejection Port Cover Kit (part no. 55BA6E3) is a direct-fit replacement for the spring-loaded flap that shields your AR-15’s ejection port from dirt and moisture between range trips. CMMG machines the cover from black 6061-T6 aluminum and includes the hinge rod and spring needed to complete the install, so there’s nothing extra to source. It swaps in using the standard AR-platform layout, keeping the action closed off to grit and moisture whenever the bolt is forward.

Key Specifications

• Machined from black 6061-T6 aluminum for a durable, corrosion-resistant cover.
• Sized for the standard AR-15 ejection port opening.
• Includes the hinge rod needed for installation.
• Includes the retaining spring needed for installation.
• Sold as a complete kit, so nothing extra needs to be sourced.
• Ships at 0.065 lb, adding almost nothing to your order.
• Includes a C-clip along with the cover, hinge rod, and spring, so the full hardware set is in the box.
• Built to meet or exceed mil-spec standards for AR-15 ejection port covers.

Frequently Asked Questions

What does an ejection port cover do? It closes over the ejection port when the bolt is forward, keeping dirt and moisture out of the action between shots.

Does this kit include everything needed to install it? Yes, it includes the cover, hinge rod, and retaining spring.

Will this fit my AR-15? Yes, it’s sized to the standard AR-15 upper receiver ejection port opening.

Buy the CMMG Ejection Port Cover Kit for AR-15

A worn or missing dust cover leaves the ejection port exposed to whatever the range or field throws at it, and this CMMG kit is a straightforward, direct-fit way to close that gap back up. Order it from our Lubbock, Texas gun shop and it ships fast to your door, along with more AR dust covers.