My lighest is a Cav Arms lower at 2lb 5oz, with upper consisting of an A3 flattop with BUIS, Bushmaster pencil barrel with a Vortex hider, and a YHM aluminum FF handguard. The upper weighs 3# 15oz, putting the total at 6 1/4 lb. The only way to lighten this on up would be a carbon fiber handguard.
