Not to steer into gun talk too much here but the magazine release is on the right side, and you need to push it to release the magazine. You're probably referring to the bolt catch and you absolutely have to press that once the last round in the chamber has been fired. Otherwise your bolt just stays back once you put a new magazine in. Only time you don't need to press that is when the bolt is already closed and there's no bullet in the chamber. In that case you have to pull the charging handle.
>.> sorry for gun rant.

Anyone hear/feel anything about multiplayer, is it even remotely good?