I know what you mean. I have not done it but is something that I think a lot about doing. I will eventually do it one of these days.
Try this: Use the velocities given by let's say Exbal, after putting in all the pertinent information. Use the velocities obtained there for 0, 100, 200, 300 yards and put them in LoadBase's DRAG COEFF of ANALYZER and calculate a new drop table using the drag coefficiente and Bc calculated by LoadBase. My experience has been awesome... my results are much closer to real life and have done very little tweaking to match bullet drop at long ranges after about 400 yards. You'll see that the first 500 yards on both tables are pretty close, but as you get further away the difference gets to be more significant.
From JBM Small Arms Ballistics:
(Q) Why can't I calculate BC from bullet drop at different ranges?
(A) You can, but not very accurately. If you look at the bullet drop for two bullets, one with a BC of 0.5 and the other with a BC of 0.55, you'll find that the bullet drops at 300 yards with a muzzle velocity of 3000 f/s and a 100 yard zero, are -10.9" and -10.7" respectively. So if you can shoot groups less than 0.2" at 300 yards, have at it. Of course you'll still only know the BC within about 10% (the BC calculation CGI can be as accurate as 2%!).
Jesus Christ the same yesterday, and to day, and for ever.
Our Lord Jesus said that as it was in the days of Noah and
also as it was in the days of Lot so it shall be in the days...
It's happening again!!! God sent to us His prophet, and His Word
to this generation and we once more are rejecting it as was prophesied!!!
---> As promised, God Sent His Prophet to us!