I’m curious.

I figure a typical Nerf dart shooter works as so:

1. A dart with a plastic cap and a hollow center
2. Putting the dart in a thin cylinder, with the cap facing out
3. Pulling back a larger cylinder that fits around the thin cylinder, where the larger cylinder is capped at one end
4. Suddenly releasing the larger cylinder, so that it will be propelled forward
5. The air between the two cylinders is compressed, and forced into the cavity inside the dart
6. The compressed air forces the dart out of the thin cylinder

I think this is doable with 3D printed parts and a rubber band.