The jigs in question are a lot more complicated than I think what you are imagining. If you look up on the topic (and possibly get added to a watchlist), it’s fairly sophisticated equipment being created to handle a lot more of the finesse work required to produce a ghost gun that can actually reliably hit targets its aimed at.

Thats what separates this sort of work out from your run of the mill DIY handcrafted stuff, the guns in question actually have a lot of accuracy as 3d printed rigs can have very high precision once they have been fine tuned, and unlike stuff like paper they can be produced in 3 dimensions, which means you’re working with a lot more than just following lines.

Think more like extremely augmented drill presses and routers and shit that can produce a lot of the parts you normally cant make yourself and have to buy.