upgrade stocks m1a

Does anyone here know what JUST the synthetic stock of an M1A Scout weighs ? My M1A setup, stock from S/A, with a 2.5-10 Trijicon scope weighs in just over 12 pounds. Something is not right because S/A says the rifle weighs 8lbs, 8 ozs. The scope weighs around 1.4 pounds. Its weight is...