There really is no "math" you can just read the chart Ted created
View attachment 7425231
if you use 1.0 Mils to hit 300 yards, Point of Aim, Point of Impact,
moving to 400 you start with 1.7 Mils, after shooting and determining point of aim, point of impact at 400, you use that number to give you the 500 yard starting point.
it's trued and verified data, that fills in the blanks for you, it's gravity, not bullet weight, BC, muzzle velocity, sight height, twist rate, bullet length, azimuth to target, it's just gravity, that is it, you use the confirmed data from the previous yard line to line up the next 100 yard target.