Ok now when you guys do load development do you chronograph all them while working up and pick loads with the smallest es and sd and tune the group with small charge weight change or seating depth changes? Or you pick the best group go with it and chronograph that? I have one of the older Caldwell chronographs and my cousin has the new one that’s upside down. Now we chronographed his loads with mine, and now he chronographed the same load about the same temps and mine read 100-150 FPS faster what would cause this? Now I have thought about upgrading to the magneto speed chronograph but was wondering if it strapped to the end of my surpressor or barrel would change the groups?