premise there. If you have a large ES or SD, your groups will tend to string vertically. By ladder testing, you can identify the most forgiving range of charge
Please excuse my ignorance but what is ES or SD? and what is ladder testing? What I don't understand is when I reload I use a digital powder scale, all my powder charges are EXACTLY the same amount every time. I measure each and every charge and sometimes I still get 50-60 fps difference in a 4 shot group,why?