i don't know if i'm being thick, but in a pump marker, surely if there is enough torsion in the spring, there is no need for any form of gas?. I understand that in many markers an airsource is required to both recock the marker, and fire it off, but if there is arround 300foot pounds of torsion in the spring, it wouldn't require any form of airsource. I found a bit of pipe and after i managed to slice the ghetto pod in half (a sad day ) i thought i'd need another project for those lazy, hungover days of summer. So, does a pump marker require an airsource, if it has a powerful spring in it, recocked, much like a bb gun?