Big deal, I made one out of some electromagnets made from wooden spools, copper wire, and a pencil as a projectile when I was in grade school 40+ years ago.
The engineering problems and questions involved in making a _practical_ gun are big. How large are the capacitors? How long do they last? Where does the power to charge them come from? How long does the barrel last? What does the cooling system look like? What happens if “something goes wrong” with the control electronics (hint: the energy has to go...somewhere)... so, having one in a lab shoot one time vs having one that can shoot at least several times a minute that is reasonably portable, maintainable, and relatively safe to the operators are two different things.
The wooden spools attract the wooden pencil when energized by the copper windings?
Kool!.