Center for Security Forces (CENSECFOR) Operator Training – M16A3/M4A1 Service Rifle Practice Test

This item tests your knowledge of the AR-style rifle’s protective ejection port assembly. The spring-loaded metal flap that sits over the opening where spent brass exits is the ejection port cover. It stays closed to keep dust and debris out of the receiver when the weapon isn’t cycling, and it automatically opens as the bolt cycles so the spent cartridge can be expelled through the ejection port. After the casing is ejected, the cover springs shut again to protect the action. The forward assist and magazine release are different parts with unrelated functions, so they don’t serve this purpose.