Yep, the primary wing feathers are the prefered feather, but I've used the secondary feathers for my bamboo arrows and they fly well, but don't last near as long.

Make sure that you use either all right wing or all left wing when you fletch up your arrows. If you're using a jig and want some helical in the fletching, make sure that you use right wing for right helical and left wing for left helical.

Make em sharp and shoot em straight, or leave em home.