So far this rocket has flown 4 times. Estes 1/2A3-4T twice and twice on some older Centuri 1/2A4-3M motors I had kicking around.  Both worked fine.  The first version I built using popsicle sticks as fins and the second version had fins made from balsa though soaked with thin CA. The second version used 24" or so of Glide dental floss, the teflon stuff, as shock cord instead of Kevlar®.  It's much cheaper than Kevlar® for the same results. It also had the finish wrap with fins painted in "White-Out".  I forgot to include a streamer in the second version and the rocket landed on pavement with no damage at all.

It's a real hoot to bring out to the range head and have people look at and wonder what the heck it is.