hot a hole into a cardboard box, I didn't think it was weird until I shot my friend and it left a paintball-esque welt. And I use a single 00 buckshot pellet as weight. So sorry about that, I only use them to penetrate cardboard armor now, so if I see someone with cardboard on the field, consider yourself warned...
Well, that's good I guess. I think that cardboard armor kinda defeats the purpose of using foam darts, though. It's not about causing pain. It's more about marksmanship and strategy.