In case anbody is interested, Jorg Sprave from the Slingshot Channel (he makes all manner of shooters powered by latex bands or tubing) reports very high velocities with elastic tubing... I've seen figures over 600 fps, if the latex is properly heated before shooting. The only problem I can see with latex for a power-source might be inconsistent velocity from shot to shot. If velocity is variable from shot to shot due o temperature or chemical degredation, that might seriously detract from viability for accurate shooting. So maybe we're better off at 200-300 fps if we can get consistent velocity from every shot. Opinions?
Geezer, stirring the pot.