Blowgun dart with fins

thingiverse

Trim fins or back of dart to whatever size you need, I did this so you can use several sizes of pipe. If you want to impale, put any nail at least 3 mm thick from the back of dart and push in, also use glue to stick the nail in. To break glass and stuff just use the handle of a screwdriver to hammer a BB from a metal BB gun in, 2 or 3 mm should work.