Determining true BC
I have been shooting with good results the Hornady 110gr V-Max through my Savage 12FV this spring and have taken a few groundhogs with it so far. I wanted to work out a real drop chart and get an idea of what kind of groups I might expect beyond the 200 yards I have been working at so far so I took advantage of a nice calm morning today...can some of you that are more experienced at this tell me if my logic is valid here?
I first made sure I had the rifle well zeroed at 200yards. I checked my 200 yard groups through the Chrono and got the expected 3145fps with very low ES(5-10).
I then moved out to 400 and used a free ballistics program to get close on how much to come up on the scope. After shooting a 3 shot group I adjusted the scope to zero at 400. I shot a group to confirm and had a good zero at 400 yards.
I used the actual come up to adjust the BC of the bullet in the program until the programs numbers matched my own.
I then moved back to 500 and used my new BC in the program to bring the scope up. Hits were exactly at the correct elevation on target.
Heres what I found hard to believe, if I did things right, my actual BC is .286 instead of the .177 claimed by Hornady. it seems hard to believe that my real BC could be 60% higher than what is claimed by Hornady.
By the way, groups:
Groups at 200 are round, at 4 and 500 most of the dispersion is windage, very little elevation.
Darn good for a (relatively) cheap rifle and Bushnell scope! All I have done is bed the action in the factory stock and open the barrel channel up to make sure it can not touch.
Thanks for checking my method!
"My greatest fear is that after my demise my wife will sell my guns for the price I told her I paid for them"
-don't know where it came from...but true