Don’t be afraid to click. Changes in lighting, contrast, and your own body mean that you will be clicking not only when you change ranges, but also as a match or training session progress. There’s no such thing as a “zero” or perfect sight alignment for pistol shooting. The point of impact with the exact same pistol and settings will change from shooter to shooter, as we all size differently and the relationship of our eyes, body, and sights change from person to person.