My idea is to create a small hand held rubber powered trebuchet. It would have some sort of a rifle stock and a highly reinforced arm (maybe using some of the thicker carbon fiber tubing as found at model airplane shops.) The rest of the idea is to make a very light weight but very strong sling using some 100 lb test spectra fish line. I am still thinking about what to make the actual sling pocket out of. Maybe just weaving a small pocket out of the same Spectra line would be best. Anyhow, the point of all of this would be to have a device capable of throwing a small metal weight at a very high velocity with no need to have a long rubber draw length. The caution here is of course that calibrating the release mechanism will be critical if you want any sort of trajectory accuracy. Another caution is that this would create one hell of a brutal whip! With a heavy rubber band driving such a thin light weight piece of line it might be able to whip around so fast that the line alone could slice off a zombie finger or head (or yours if you aren't careful) So there it is, just a little inspiration. Please please be very careful with this one. Slings are amazing leverage tools but carried to extremes they can be down right scary.