AFTE Store - The Sound of Bullets

Firsthand observations and instrumental recordings reveal that even small caliber projectiles such as .177 caliber pellets at relative low velocities (e.g.- 350f/s) produce audible sounds as they pass an observer’s location so long as the distance from the responsible gun is sufficient that the sound of the projectile’s passage is not masked by that of the discharge of the gun. This requirement, and the ability to produce audible sounds at downrange locations, is also true for larger and more powerful guns. Bullets that are supersonic as they pass a downrange subject produce a loud, sharp ‘crack’ that can only be heard after the bullet passes the listener’s position. This sound is similar to the sharp ‘crack’ produced by a bullwhip and it is exactly for the same reason- the tip of the bullwhip has gone supersonic. Subsonic bullets, on the other hand can often be heard as they approach, pass by and depart a subject’s location. These sounds are quite different in character and intensity. These bullets frequently produce a hissing sound and are much less intense that the loud ‘crack’ of a supersonic bullet. In cases where an audio recording has captured both the sound of the bullet at some downrange location and the distant report of the responsible gun, it may be possible to calculate the distance from which the shot was fired from the time differential between the two sounds.