Wind and drop comparator
Drop is a dial setting you look up once. Wind drift is the number that decides whether you hit, and it is the honest way to compare two match loads. Enter what is printed on your boxes and see the difference at distance.
Conditions
Loads
Ballistic coefficient and muzzle velocity come from the box or the manufacturer's product page. We deliberately ship no preloaded values — a BC we cannot source is a number we will not publish.
Results
What this actually calculates
A two-degree-of-freedom point-mass trajectory, integrated numerically at 0.4 ms steps using the standard G1 or G7 drag function. Retardation is a = ρ · Cd(M) · v² / (2 · 144 · BC), with air density from your temperature and altitude, and speed of sound from temperature.
Launch angle is solved numerically until the path crosses the line of sight at your zero range, so drop figures are true come-ups from that zero rather than raw drop from the bore.
Wind drift uses the standard lag formulation: drift is crosswind speed multiplied by the difference between real time of flight and vacuum time of flight. Full-value means a 90° crosswind — angle it and scale by the sine.
What it does not model
- Spin drift and Coriolis. Both matter past roughly 800 yards; neither is included.
- Aerodynamic jump, vertical wind components, and terrain effects.
- Humidity, which changes density slightly and is dominated by temperature and altitude.
- Your rifle. Real muzzle velocity varies with barrel length and temperature, and velocity spread is what actually opens vertical dispersion at distance.
Use this to compare loads against each other, which is what it is good at. Confirm a firing solution on paper or steel before you trust it.