Great rocket! Two awesome flights so far including one at NARAM-50 right after the rain storm.  I built this kit stock although I did add a 38mm Slimline motor retainer.

2011 Notes:

I cut down a stock PML QT payload section to 7" and scratch built a mount to hold the Adept A1E altimeter. I added a couple strips of masking tape to the nose cone shoulder for a tight friction fit in the payload section, but I probably need to take the time to install a more positive retention system (like plastic rivets or t-nuts and screws).

Jan 2012 Notes:

OK - I think the Callisto is one of my all-time favorite rockets!  I really like the ease of prep for flying - the piston is super simple to use!  I do take the time to clean out the airframe after each flight so the ejection charge residue won't cause the piston to stick.  I really like the altimeter mount in the payload section - I install the battery in the A1E, drop the A1E in the payload mount, then pop on the nose cone.  Quick and easy!