No
The ejection port is always open, the bolt is closed when a round is in the chamber when the round is fired the bolt recoils and the casing gets ejected. What I think you are talking about though is the dust cover. It stays closed until you fire a round and then it stays open until you physically push it shut again.
Ok just re-read your orginal post. But I answered it anyway..... just terminology...... it is generally refered to as a dust cover and does not open and shut after every round
