
Basically the idea is that using the power of elasticity you could store kinetic energy in a spring or rubber band or other such elastic material, and have the dart be pushed right against the clip by the spring causing it to be stored under lots of pressure which would then be conferred to forward momentum when the dart is allowed to travel forward by aligning the shell with the barrel. So with that in mind all you would need theoretically is an advancing mechanism which could keep the shells from spilling out, or other things you wouldn't want to happen. Now I realize that this idea most likely will not have really great ranges, unless you find some really good springs to fit in your brass shells and that you need very dense Stefans to withstand being flattened by the spring but semi-auto at medium-close range while using a primary is nothing to laugh at. Suggestions welcome.