...what Da Rock said.

These launchers really do work well, as long as the catch works freely AND holds the model until you want it released. Make sure of that. I had to play with mine until it did what I wanted it to. BTW, the space on mine where the model's tail loop goes is way too wide, I need to make it narrower. The less distance the pin has to travel the better. I have been meaning to do that for the past ten years.