When I chrono my 300 WM load with the Berger 210 VLD's it averages around 2920 fps. I set the chrono 15 feet from the muzzle. But when I go to the G7 Ballistics Calculator and confirm trajectory at 400 yards it wants to either change the published BC or speed up the bullet to 2985 fps. Which should I trust, my chronograph , the published BC from Berger, or the G7 Ballistics Calculator?
I have used many 300 wins with 210 Bergers. A max load of H-1000 will get me just over 2900 from a 28" barrel. Using the Shooter app and the factory BC of .631 it worked out with drops to well past 1000 yards.
But, I say, never, never, never, trust the chrono (unless maybe ya paid big bucks for it) UNTIL drop confirms velocity.
The chrono that is usually used will get you in the ball park. Drop validation will get you spot on.
I'd use Jeff's bc value then validate.
Agreed. It is always about trajectory validation. You do have to do your due diligence in setting up the validation correctly with correct inputs for atmospheric conditions, load data, etc. but once you get that down you almost don't even need a chrono. I have gotten pretty good with just loading for accuracy, guessing on velocity from published load data to get me close, then validating trajectory to determine my drop chart, velocity, and shooter ap inputs.