Will probably be picking up a KSC Glock 17 locally soon. Before I do I need a bit on consultation on an issue it has. According to the owner when the gun is cocked while upside down the entire slide assembly will fall off the lower if there is no mag. When there is a mag or is oriented correctly it works fine. Has anyone encountered something like this before? I'll be able to test the gun in about a week and I don't think it's a deal breaker but I'm not experienced in this area. Any help is appreciated.