Potatoes just aren't quite the ideal projectile for distance.  Something that would be sleek and travel very far is ideal.  These darts are 3/4" thin-walled PVC by 24" long.  There is a nose cone (from a model rocket), and it has four Fins that are at a slight angle. This angle in the fins cause the dart to spin through the air like a bullet and maintain longer flights.  For the fins I used a flexible plastic sheeting from a binder; the binder is the kind with the flexible plastic cover.  I cut the slits for the fins using a small dermal tool. Because of the light-weight design, the dart floats through the air, which makes the projectile achieve great distances. This dart is used with the P.A.C. 5 and easily can fire over 1000 feet.

Here are some various pictures of darts

(Picture of the fins.   Notice the angle)

(The orange makes the projectile easier to see against the sky)