FX Dreamline classic or lite is under 6 lbs. STO on here makes mods that are extremely light and effective will cut even more weight over an aluminum mod.
For what it's worth. On a .25 Dreamline. If you max the hammer spring, it will shoot a 34g mkII at 50 fpe. Turn the hammer spring down two clicks and 25g at 45 fpe. Turn the power wheel to low and I can shoot 20g H&N at 20 fpe and save air while plinking. I sold my AT44 to cover some of the costs. It was a nice gun but too heavy and this one does everything.