Yankee Hill Machine Co YHM Dust Cover Assembly 300 BLK – AR-15 Ejection Port Cover

The Yankee Hill Machine Co YHM-111-300 dust cover assembly is a replacement ejection port cover marked for 300 Blackout chamberings. This assembly prevents dirt, debris, and moisture from entering the upper receiver through the ejection port when the rifle is not in use or being transported. The 300 BLK roll mark provides a clear visual indicator of the chambering, which is a practical safety feature when maintaining multiple AR-platform rifles in different calibers.

Constructed from mil-spec materials with a black finish, this dust cover is a direct drop-in replacement for AR-15 and AR-10 pattern rifles chambered in 300 Blackout. Installation requires basic tools and familiarity with AR-15 assembly procedures—the spring-loaded rod simply pins into the upper receiver. The assembly includes the cover, spring, and C-clip for complete installation.

• Part Type: Ejection Port Dust Cover Assembly
• Compatible Firearms: AR-15/AR-10 pattern rifles chambered in 300 Blackout
• Material: Mil-spec steel
• Finish: Black
• Marking: 300 BLK roll mark
• Installation: Drop-in with basic tools
• Includes: Dust cover, spring, C-clip