Hello, I'm new to the board and the ar-15 platform. I purchased a new S&W MP-15 and have been learning a lot about it on here, but I just had one simple question. If I do not have a magazine in the gun when you cock the bolt back should it catch like it does when you have a magazine in it? When I do not have a magazine in it I have to manually engage the bolt catch. Is that correct? Thanks a lot in advance.