A ballistic app tells you what the drift is for your bullet in inches/mils/moa/whatever...u can adjust the wind values and look once you have your BC trued up
the problem is the wind isn’t constant or consistent... so even tho you know what the “theoretical” drift should be, it won’t always match...there are even apps u can put in various wind zones, but how accurately can u measure them? Unless you’re rockin real time lidar, you’re just taking single points of reference and making the best guess
the range/terrain conditions you shoot in will also skew how accurate your inputs are
View attachment 7302844
the red circle below is inches...you can adjust the wind values from the first pic to 1 mph for the entire 0-1000 yds and it’ll tell you how much it drifts @ any range for that 1mph