The Yankee Hill Machine Dust Cover Assembly (brand part no. YHM-111-9) is a complete AR-15 ejection port cover marked specifically for 9mm chambered rifles. Machined from steel, it replaces a worn or missing factory dust cover and keeps dirt and debris out of the ejection port when the bolt is closed. The 9mm caliber marking makes it easy to identify at a glance, a real advantage for owners running multiple AR-15 uppers in different chamberings, including 9mm pistol-caliber carbine builds. It ships as a complete assembly, not just a bare cover plate, so it is ready to install without hunting down individual small parts.

Key Specifications

• Machined from steel for a durable, factory-style dust cover.
• Marked for 9mm chambered AR-15 rifles and pistol-caliber carbines.
• Built as an AR-15 accessory for standard ejection port openings.
• Classified as a Dust Cover product type in YHM’s catalog.
• Includes the installation rod needed to mount the assembly.
• Includes the retaining clip that holds the assembly in place.
• Includes the spring that snaps the cover shut over the ejection port.
• Sold as a complete dust cover assembly, not just a bare cover plate.
• Direct replacement for a worn or missing factory AR-15 dust cover.

Frequently Asked Questions

What caliber is this dust cover marked for? It is marked specifically for 9mm chambered AR-15 rifles.

Does this include the installation hardware? Yes, it includes the rod, retaining clip, and spring.

Will this work on a 9mm pistol-caliber carbine? Yes, it is marked for 9mm chambered AR-15 platforms, including PCC builds.

Buy the YHM Dust Cover Assembly

Keep your 9mm upper properly identified and protected with an assembly from Yankee Hill Machine. Browse more upper parts in our AR dust cover category, and order it from our Lubbock, Texas gun shop for fast shipping.