I've been dabbling with Arduino microprocessor. Tales of my reloading counter are elsewhere. I'm experimented out with lighting programs, clocks and counters. I did get a rotational position indicator to experiment with the idea of knowing exact reloading press position. Decided "nah" too much trouble to little pay back but I did learn how those work.
In the meantime I looked around
http://robotshop.com thinking my next learning adventure will be with stepper motors.
All of this is to say I get targeted ads from Robot Shop now on FB. The latest? A complete Doppler Radar module. Just a hair over 1" in diameter. Make your own radar gun to suit your own purpose. This one probably won't measure bullets at velocity, but still it's only $34. I'm still having trouble going from a room full of equipment for a 16bit 256K computer to a palm sized module like Arduino. Blows my mind what's now available.
https://www.robotshop.com/products/iot-radar-module-xm122