Here's your choices:
A. Use the chrono readings to create the drop chart and don't worry about actual drops.
B. Forget the chrono and develop the drop chart by shooting @ several ranges out to the maximum range.
Which of the above will result in successful harvest of more game? Yep, you guessed it!
One of my rifles chronos @ 3440 FPS but Shooter to make the drops hit the targets says to use 3040 FPS. And no I don't have it figured.
It just works.
Oh, and this is with a second barrel on the rifle which with the original bbl and same custom bullets used the same bc and the chrono reading of 3440.
Can barrels change bc that much???
I use the chrono for ES and SD only and that is trumped by watching vertical dispersion at very long distances.
Real world ballistics trumps calculated values.