Hello everyone, got a question for ya'll if you can help me out. I'm trying to learn how to calculate wind drift. I have found a Army formula of (range/100) x wind velocity / constant. My question is how do you find out what the constant is for the rifle and load? Is there some formula for figuring it out or is it just off of range experience? I shoot a 300 win mag with 165 grain Nossler Accubonds that have a B.C. of .475 and it is has a muzzle velocity of 3200 fps. Any tips would be very helpful. Thanks.