Rail/coil guns are much harder to build than they sound. You need some damn big caps for a coil gun, and while a rail gun can get away with slightly smaller caps they require mechanism to fire the slug into the rails at the minimum speed for acceleration.
@Miles_Wilford
Thanks, I might call it a part of a gun, but sometimes I wonder if they can do the whole gun though, if possible.
@Sam_General_Falcon In a word: no. At least, not yet. Basically, they are making the scaffold that everything else attaches to. If they spring for an ARCAM EBM 3D printer, they might be able to print in steel or titanium the parts the more difficult parts, but I’m not sure the accuracy is up there yet. The powder printers output stuff that can take basically no shock, its kinda a weak ceramic when its done, and the plastic from an FDM machine cannot handle the pressures that are routinely seen in a gun chamber.
Well, you could make a hand cannon type of deal out of anything. See the mythbusters duct tape cannon.