Sorry to take so long to answer, I had a brain fart and couldn't get the right safe open. It helps if you put the right combination in the corresponding safe.
My post ban 16" expedition with post ban M4 CAR stock weighs 6.8 lb., my 20" with RRA trigger group installed weighs 7.8 lb.
Basically on this batch the weight difference between the standard HBAR and Expedition is 1.64 oz. on the 20", 2.5 oz. on the 16".