Yeah, the tightbore 6.03 and 6.04mm barrels would give you an extra 20-30fps but the customer must use the highest quality ammo available and clean the barrel regularly. I can see why they'd drop it to 6.08 (stock airsoft) or 6.10. I would be game for the recoil units and guns, not whole tanks. Still curious to see what else they've got coming out.