Aiming for sub 7 lb carbine (no magazine) with optic and MBUS. 14.5" pinned lightweight barrel and a 12" <9 oz rail should get me those numbers. My 16" regular barrel with a 10 oz rail sits at 7.2 lbs with microdot and BUIS.
Next purchase will be the BCG. Not sure if I'll go standard in NiB, or go fancy (and potentially gimmicky) E-BCG from Blacklist Industries or Lantac.