Thanks for the reply. I know the aerodynamic theory well, what I don’t know is the weapons parameters.
I still don’t understand the zeroing. For example, if I consider 25 yards as zero it would miss trumps ears. At the end I’m only looking at the ballistics, to estimate the drift and drop at the 180 yard position (where the 1th victim was), having knowledge that it hit Trump at 153 yards, where it must pass at zero.
(edit) I tested scenarios varying drag coefficient from 0.14 to 0.4, velocity from 3050 to 3200 ft/s, weight from 40 grams to 77 grams, altitude from 0 to 1350ft, using both calculators. The most probable scenario is 1 inch drop at 180 yards varying from 0.7 to 1.4 inch, considering zero drop at 153 yards. For the drift the medium scenario at 180 yards is 1.5 inches to the East varying from 0.7 to 2.3 inches.