This is a modular multistage low voltage reluctance coil gun. Each module has 14 stages comprised of asymmetrical Mosfet full-bridges. For the two modules shown in this video the total energy transfer efficiency from capacitors to projectile is 6.2 to 7.5%; about 2% for the injection coil, about 12% for two modules (28 stages).
Velocity varies depending on projectile mass. For two modules it's more than 200ft/s.
Coils are switched in sequence according to projectile position with a constant current of about 300A.
This is a low voltage design, the capacitors are charged to 50V from a 4S LIPO battery.
![](https://s2.save4k.ru/pic/dW19xTn-36k/maxresdefault.jpg)