Make sure that the radar gun has been properly charged before you begin using it. Otherwise, you may get false speed readings when using the radar gun.
Set the mode for the radar gun. Most radar guns will have a "continuous" and a "trigger" mode. The continuous mode allows you to detect the speed of an object without having to press any button. This method is often used by members of the highway patrol. When the radar gun is set to trigger mode, you will have to press the trigger of the gun each time in order to detect the speed of an object. Baseball coaches usually prefer the trigger mode of a radar gun.
Stand at least 25 feet away from the moving object. This helps to ensure that you get a proper reading. How far you stand away will be determined by how far the detection capabilities of your radar gun extends.
Point the gun so that the object is either moving directly toward the radar gun or directly away from the gun. In other words, if you're determining the speed of a pitch, you should stand directly in front of or behind the pitcher so that you can draw a straight line from the gun to the baseball.
Press the trigger as the object approaches (or moves away from) you. The radar gun will "beep" and the numbers will appear on the screen. Those numbers indicate the speed of the moving object. If the radar gun is set to continuous mode, you will not have to press the trigger as the gun will automatically detect the speed of the object.