I have an ingenius idea for a spring airsoft mortar. I just have one MAJOR question that I would EXTREMELY appreciate being answered. Where is it possible to get a spring approximately 2 feet long with good strength and a diameter of approximately 1in to 1.5in? Nothing has to be exact, I'm just asking for an approximate estimate. It will launch easter eggs filled with airsoft BBs. No pyrotechnics will be used. (Mods, bear this in mind) The force used to break the egg will be gravity, air friction, and momentum. Here is a photo of my sketch design. It should be basic to understand. Just bear in mind that this is a basic sketch, not much in detail.