The Spring resides in the center of most drums and using a spinning or rotating motion instead of pushing or compressing the spring, which is what happens in a magazine. You would be Twisting it as opposed to pulling of pushing. The spring would wear out as all springs naturally do, but you'd only need a spring slightly long than a dart. The spring probably ought be a little thicker than the usual spring used in Nerf If you get one as short as a dart though.
-Edit.
You could use gears to rotate the Mag, with a toothed bar attached to the cocking/pumping mechanism, and a series of gears placed on the mag, with a toothed exterior which would eliminate the need for a spring in the mag at all. This would eliminate the possibility of your spring crushing bare ammo. The biggest problem would be in the event that your Mag was damaged, repairs to the exterior or the gears could be time consuming depending on the damage.
Pros: No Spring, No threat of crushing ammo. No Jams due to deformation of dart due to spring.
Cons: Gears Must be aligned properly or you're in for a tough game. Repairs could be difficult.
Edited by wardrive, 15 February 2008 - 06:26 PM.
It's not called incompetence, We call it Leadership.