I recently saw the steps to make a thistle dart and it seemed very involved and technique dependent, I'm not sure I'd have the patience! I seem to remember you use them in competition shooting and it also requires a special kind of thistle too?
Great links to nail/sabot dart builds ...that also included the fps numbers and how speed increases with practice, a surprise! I would expect accuracy to improve with practice but was surprised to see how much dart speed does too!
Is a straw used to stabilize the dart in flight, is that why you use them and not shoot plain finish nails?
Pelletor, sorry, I just saw this today. Yes, in answer to your question, the straw is used to stabilize the dart in flight. If you just shoot plain finish nails with no stabilizer, they will tumble in flight. The straw stabilizer darts can be quite accurate at 10 yards. 8 penny nails usually weigh about 40 grains or so and will penetrate a lot of things surprisingly well, plus the blunt tip creates quite a bit of impact. If you really want to try shooting the straw-stabilized darts at long distances, I'd recommend trying to make something similar but with a sharp tip instead of the blunt head.