Calculating Ballistic Coefficients
Ballistic coefficients can be found in reloading manuals, but they can also be calculated from two velocities and the distance between them, or from a velocity, T.O.F. (Time Of Flight) and the distance between them. Before calculating a bullet's ballistic coefficient, enter the altitude, temperature, pressure, humidity, wind direction, and wind speed that existed when the data was acquired. This allows Ballistic Explorer to correct the ballistic coefficient to standard sea level conditions. If you don't know what the conditions were, use the standard values.
Click the Options button and then click Calc Ballistic Coef to open the Calculate Ballistic Coefficient dialog box.
Select either the Velocity / Velocity Method or the Velocity / T.O.F. Method. Then enter the data into the corresponding edit boxes. Note that the distance can be in feet, yards, or meters by clicking on the desired unit of measurement. Click the Calculate button to calculate and display the BC without returning to the trace window. Click the Apply button to calculate BC and return to the trace window with the calculated value in the BC parameter. The calculated BC corresponds to the selected drag table, which is usually be G1.
The Velocity / Velocity Method is useful for calculating BC from published ballistics data where the muzzle velocity is given along with velocities at specified distances downrange.
The Velocity / T.O.F. Method is gives BC values that best matches the bullet's trajectory when muzzle velocity and the time of flight to a specified distance is given.
With either method accuracy is increased when using longer distances out to 1,000 yards.