Why? Honestly I don't know. I get weird ideas and I just happen to have the ability to make them. I guess if you flew RC planes you could paint them u...p nice or drop them on squirrels at the bird-feeder. Besides, I got lots of these lying around.
Seems to be quite a workout for slicer. There is some sort of weird artifact in one of the fins possibly or the retract is off on my printer. As far as I can tell everything looks fine though. Sketchup file included if you want to mess with it. Friction fits onto the canister. I guess you could paint a dartboard on a chunk of drywall and whip them at it..... where did I put that cannon fuse?...hmmmm....
3d model print parameters
Empty (Or full!) 12 gram CO2 canisters....PLA, printer....