What I would like to see . Is which rifle really requires less air useage or work with a hand pump to refill between the dual and single tube . We do know that you can get a few more shoots out of the dual before filling . But does it take more air to refill after the psi drops off . . Air usage per shot . Should help answer that question . Then there is the energy difference between the two rifles . So a comparison between a stock single to a tuned dual might have to be considered as well .Marvin