At $1.99 for a pair, I of course grabbed a bag containing one rocket with a black body, one with green. When I got them home, I quickly assembled motor mounts for featherweight recovery (that is, just a plugged tube, no latch) from 1.5 inches of BT-5 and end caps made from the center pieces of the centering rings in my Prime Number Explorer kit. The BT-5 proved to need about six wraps of masking tape to fit the hole snugly; I then did a quick test, found thin CA wouldn't eat the foam, and used that glue to intall the motor mounts in both rockets.
Next it was off to VCP to check the CP locations -- about 1/2" ahead of the fins. I installed a fresh motor in the mount and balanced the rocket, and found it balanced well aft of the desired location, which would have been about 1.5" ahead of the fins (1 caliber forward of CP), so I looked around for some nose weight that wouldn't destroy the softness of the foam nose. I first tried strips of match solder, but they were too thin and light. Then I hit on using some 110 grain bullets (110 grains is almost exactly 1/4 ounce) from my reloading supplies -- and they were just a little heavier than needed, but not bad. To install them, I used a hobby knife to cut out a plug from the center of the nose, dropped the bullet into the cavity (with the flat base toward the nose of the rocket), trimmed the plug to fit, and then glued the bullet into the cavity and the plug on top of it with thin CA.
Last, I glued on a 2" length of 1/8" launch lug centered on the new
balance point (with motor installed). I haven't have a chance to
fly these rockets yet, but I should be able to do so on 14 February.