Originally Posted by ThunderCactus
Shitloads. It costs exorbitant shitloads.
Just use propane.
Edit: an 8oz can may get you quite a few mags - maybe you can eek out 30-50? I'm trying to remember how much I go through off the top of my head.
Depends on the mags as well. Some mags hold more gas than others. Some gas systems use more gas than others.