Early chronographs

Guns Magazine, July, 2008

Q: This question has stumped just about all of the "soot burners" at our range. How was muzzle velocity calculated in the days before modern timers and chronographs?

Ron Odum

Long Range Alley/Trinity Tactical Institute

Grand Cane, Louisiana

A: Prior to man's harnessing of electricity, there was no practical way to measure the velocity of a bullet. According to W.W. Greener in The Gun and its Development, the first chronograph was the Navez-Lours, which consisted of two pendulums suspended identically. The pendulum's swing could be arrested by electrical magnets on either end of their swing. The circuit was completed by a screen. One screen and pendulum was set up in front of the gun and the other screen and pendulum 120' away. When the bullet passed through one screen the pendulum swung free. As the bullet passed through the other screen, its pendulum swung free and the difference in time elapsed between the fall of the two pendulums was recorded and used to calculate the speed of the projectile in feet per second.