Not sure there are any moving parts on it besides the switches. It could have solenoid strikers but that would mean it needed primers. Those would be near impossible to source and a master class DIY. More likely the batteries run nichrome wire igniters inside each barrel. If you look at the "breech" ends you see wires going in. Barrels look like IMC rigid conduit or water pipe, either strong enough for the lazy pressure spike from black powder. And that is most likely DIY (2 or 3 part) or taken from blanks (nail gun & stage prop).

/gun bans, not likely