I have been having a lot of fun playing with piston launchers this year. Starting with the Sunward kit I rapidly moved on to building my own from scratch. Fixed head and floating head pistons with internal wiring. I even started turning my own pistons from brass and aluminum. But with all the information I found not much on piston volume is out there. I hope this question makes it to some one with a little more experience. So here is the question based on a floating head piston. Do you get more velocity off a short piston tube with the rocket popping off before the head is pulled from the center post? Logically if the head is pulled the rocket is leveraged against the mass of the tube not the launcher. The tube would be accelerated in the opposite direction absorbing some of the energy. I know a longer center post and tube provide more stability but I am just asking about motor performance.