I'm imagining some folks here have to have researched this: Wouldn't the momentum of a slingshot projectile come almost entirely from the initial moment of release? In other words, a shortened band stretched to its max should provide exactly the same speed leaving the sling as a longer band at equal tension - after that first release moment, the rubber instantly loses the power it was providing. To wit, a 10" rubber pulled back a foot might provide 100fps. Pull it back two feet, and it might provide 140fps. So when released from a two-foot pull, as it passes through the one-foot pull zone it cannot provide any more momentum than at release because, at that point, it is providing less momentum than the projectile already has. So the objective has to be to get maximum stretch from a short segment of rubber. Longer stretch, if not providing more tension, won't give any more speed. I'm thinking of this in terms of the various slingshot Xbows and rifles etc. The length of draw could certainly increase your accuracy, just as it does with rifles vs pistols. But unlike guns, where the burning powder keeps increasing pressure (and therefore projectile speed) as the bullet travels the length of the barrel, with slingshots the bands LOSE power long before the projectile has passed the 'muzzle'. So I was wondering why Jeorg's sling xbows do not have longer 'barrels'.... now I get it.