I made this simple wooden test bed to hold all the parts of the coilgun securely. When firing there is some recoil so it’s good to keep everything in place.

The small PCB on the bottom left is a mystery chinese DC-DC boost converter. The control chip had it’s part numbers ground off but I manged to read them under a bright light and it’s a flyback based design. Takes 5V in and gives a nice 300-400V which is perfect for capacitor charging.