I saw a similar effect on CSI once…. they had a bullet trail that was a spiral that looked very cool… I recreated the effect and it came out perfect…
all I did was create the bullet in Photoshop, and also make the spiral trail which was just a white spiral that was the length of the entire bullet path with a low opacity… then I brought that into after effects and made the bullet move in a 3d layer… the bullet trail was on laid over the video, and the bullet was followed by a gradient mask that revealed the trail as the bullet moved… i guess you could feather the mask for the same effect….
Hope that helps in some way….