So you run straight BC values from the box and just change MV until it lines up?
I use known, measured BC values- they’re available for every good bullet. Zero correctly, then shoot at distance near transonic or as far as I will shoot with a specific rifle/bullet ever, with enough shots to see the true center of the cone, then adjust MV to match.
ETA: how much are you changing MV from chronograph results to get dope to align? 10, 20, 50, up to 100fps?
I haven’t used a chrono for a long range hunting rifle in a very long time until the Garmin. At the S2H April class I chronoed three rifles with multiple ammo types each that I had data for by trueing at distance as above, and the largest MV discrepancy was 11fps average IIRC.
It’s not that legit chrono numbers are bad, nor is it that he BC numbers are off when using known real values- it’s that people have something wrong with the system. Zero errors, MV variation, not shooting enough shots at distance to see the true average center of the cone, slight winds when shooting at distance, their scope not adjusting perfectly 100% across the entire adjustment range, etc.
Trying to adjust BC of known, Doppler radar measured bullets by shooting them, especially above terminal velocity range- is near inanity the moment you look at and understand the possible variation in BC rifle to rifle, and the tiny differences that result in target down range.
And who said anything about truing up an inch at 800 yards?
An inch at 800 yards is what results from a 10 point BC change at .536G1 and 2,940fps MV. Thats about the max that bullet BC varies from rifle to rifle unless something is very wrong.
