Originally Posted by KY Gun Geek
Dug up my targets and chrono data - ran it all through Loadbase. Very surprising!
Input data listed below, but the net is to get the drop numbers to match, I had to back the BC all the way down to 0.33. The advertised BC is 0.43. I will do more verification of this (including down range velocity measurements). Anyone else seeing this?
Here's my input data. Please verify if you have software (to make sure I'm running it right):
MV 2890 (measured with chrono)
Drop @ 300yds: 10.75"
ZH: 0.8" (measured from 100yd target)
Bullet Weight: 225gn
If you care, atmospheric numbers:
Station Pressure: 28.78
Your numbers sound about right but I think you need more data.
The differance between a B.C. of .43 and .33 only makes about .75" at that range given your data. This small amount of differance could be due to shooting or Chronograph errors.
If you try that load at a much longer range, it will give you a far better idea of the true B.C. of the projectile.