Cock

On TV and in movies, why do people always cock their guns to show that they mean business? You know what I mean? The person will be pointing a gun at someone, and that person will be all like "You ain't got the guts," and then the person is like "try me" and cocks their gun. I mean, why don't you already have the gun cocked? Who points a gun that they can't shoot? And if it were me being pointed at with the gun, i would be all like "See. Now i know you don't mean business, because you didn't even have your gun cocked a second ago." And ultimately, the cocker would agree and that would be the end of that.