People are real douchebags on here if you want anything light. Here are some helpful answers.
Get a heavier buffer/stock, but don't get a longer stock or it'll feel heavier. Weight close is light, weight far away is heavy. Leverage. I see your stock is quite extended. Try shooting it fully collapsed. Nose to charging handle. Shorter is lighter.
Contour the barrel down will save a lot. Chop it to 14.7 or 14.5 while you're at it. You can go down to .625, .575, .560 or even .550 contour.
Get rid of the front sight post and get a carbon tube, or an NSR rail, with a low profile gas block (.625 of course).
Get front and rear MBUS. Better yet, just put on a H1/T1/RMR on the back and forget irons.
Do this and it'll be very, very light.