30m is med for bolt guns running high power, 30m for everything else is lowest range , using 30m to test barrel length accuracy, is insignificant, all air muskets are able to hit a target at 30m ,everything is needed to get accuracy, correct cylinder volume ,efficient air seal, air nozzle engagement, tappet return, magazine spring tension everything needs to be taken into account before you get to hop rubber ,nub and then barrel ,and ammo weight , you cant just remove them variables to come to a conclusion .