So, I'm currently writing a mathematical analysis of a bullet with a muzzle velocity of 790 m/s. I have found that the standard equation for drag force... Fd = 1/2 * ρ * v2 * Cd * A does not work because the drag coefficient for a bullet (.295) does not account for supersonic speeds. What I want to know is, could I substitute the ballistic coefficient into the problem in order to get the value for drag force? If not, what would be the proper way to calculate for the drag force on the bullet, assuming I know every variable besides the correct coefficient of drag? Also what is the difference between the two coefficients?