Do you mean the bullet drop at 2 different distances?
It's called "truing" the ballistic calculator. I believe the Horus Atrag software can do this. I'm sure other calculators can too.
i read that if you shoot at two different [known] distances, and measure the drop between the two, there's a formula for calculating muzzle velocity, that according to bryan litz is quite accurate..
thanks guys. i'm pretty sure it was something as simple as:
take a shot at two known distances, like 100 yrds. and 200 yrds., measure the drop in POI.
the formula supposedly figures out muzzle velocity from there.
not sure what other variables are required, like B.C., bullet weight, etc.
wish i'd been paying more attention and could remember where i heard it or read it.
D*(G/2*H)^1/2?
D= distance from muzzle to target
G = gravity 32.15 ft/s/s or 9.8 m/s/s
H = measured drop
So 100yds and 1" drop from a zero degree angled barrel= 300 ft, so 300*(32.15/2*.0833)^1/2
300*(13.91).....300*13.91=4173
Will that help you get started?
Isn't this what chronographs were invented for? Why make life difficult?
Because chronographs simply are not accurate enough. So you need to calibrate muzzle velocity.
It's called "truing" the ballistic calculator. I believe the Horus Atrag software can do this. I'm sure other calculators can too.
Isn't this what chronographs were invented for? Why make life difficult?