Shot shells pressure.. how important..

[Bruce Day]

Its called a ballistic pendulum and versions have been in use since the 1700's. There are numerous treatises about how it works that are interesting to read for those who are interested in physics. Not wanting to sound like a know it all, interested people might check the internet for explanations and details. Its basically a target calibrated for weight of the projectile that moves when it is hit and the movement relates to momentum which relates to velocity. I remember reading a naval story mentioning the huge size of the ballistic pendulum that had to be used when measuring the speed of a 20lb cannonball.

Bruce.....and that's pitifully all I know about it......and I'm no expert.