"Method of Measuring the Ballistic Coefficient of Bullets"
I just bought a chronograph (
this one), and have been playing with it. I shot a string of ten shots through it with the
Airsoft pistol (Average velocity = 307.7 fps, SD = 4.76, in case you're interested) I bought a while ago (to pop the feral cats that my mother wanted me to dissuade from hanging around our bird feeder), because that's easy and not as dangerous as shooting my real (airgun and firearm) guns for the purpose. Main reason I bought the chrono was to A) establish the distance to sight-in the real ones at to achieve my desired point-blank range, and B) determine how powerful they really are. Both of those questions require knowing the actual velocity of your projectiles (they also require knowing your bullet mass, but I already have a scale that measures that to 0.01 grams, so not an issue). They also require knowing the actual "Ballistic Coefficient" of those projectiles. I wanted to know if one could determine the BC (because most bullet-sellers won't actually tell you that, or else give you unreliable bullshit numbers if they do) if one knows the muzzle velocity and an instrumental velocity from some known down-range distance. So I googled it. And got this scientific paper. And understood it.
Yeah, the BC is calculable from two [distance,velocity] knowns. And everything else I want to know is calculable from that. You can calculate the entire trajectory of your bullet from muzzle to the point it crashes into the ground. No need to fire and measure the experiment (after the first two that you measured, of course).
The paper was written by a bunch of Russkies, though. Should I be thinking
"Marko Ramius",
Iosef Djugashvili (atmittedly a Georgian rather than a Russian), or
Nikolai Ivanovich Lobachevsky (is his name, HEY!!!)???
17th May 2020, 08:06 PM
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