I hate to appear stupid, but having no experience with 1911s, I'm wondering: Why is a 1911 considered safe when carried this way as opposed to a DAO semi-auto or a DA/DAO revolver? From what little I've been able to read, it seems that it has something to do with a sear. What is a sear and its purpose? It seems to me that you are carrying a SA semi-auto with a very light trigger pull that it could be easily fired when not meant to. If someone could explain this to me or direct me to some further information, I would appreciate it.