*This seems like a better way to make darts, from an old issue of Mother Earth News I just came across:
"To make the darts, all you have to do is lay one of the empty milk jugs on its side, and with the propane torch set at a low flame, carefully heat an area about the size of a quarter until the plastic turns clear. Then push the pointed end of the plumb bob into the soft spot and hold it there until the dimpled area clouds. Make several rows of cones in this manner (leaving a bit of room between each), and cut the dimpled wall from the jug. You can use a short piece of scrap tubing to separate the cones from the rest of the sheet. Just bevel one end of the conduit to a sharp edge, then place the plastic-points up-on your wooden block. Center the tubular cutter over each cone to be removed, and give the back of the tube a smart rap with the hammer.
Once you've freed a number of cones, it's easy to make darts out of them by pushing nails or wire stubs through the pointed ends from the inside. A dab of silicone sealant or clay set behind the metal will serve the threefold purpose of securing the point, sealing it, and giving the dart some necessary weight. A bit of research will help you to determine which combination of points and putty works best - though we're partial to drywall nails backed with silicone."