G1/G7 ballistic coefficient diffrences

[seadog]

I have seen diffeent bc' based on velocity, seen where some people take a average of the bc then plug that in the drop charts.
Seen others only give 1 bc, and use muzzle velocity to run charts with..
Seen others use g7 data...
It is still an approximation..

It really helps if you have the bc to velocity numbers for the bullet you are using.
Tell me what bullet you want to use and I will see if I have the numbers.