The Doppler radar velocity measurement of a 7.62 x 51 standard Nato bullet, fired at 38.7° shows a fast velocity decrease close to the muzzle, but an oscillating nature of the velocity for flight times exceeding 14 seconds.
It is believed that this velocity oscillation, with a frequency of 1.0...1.6 Hz can be explained by a precession instability, forcing the bullet to a coning motion.
