I think perhaps to lighten a No.1: the barrel taper/length/type(carbon fiber wrap), remove the quarter rib(two piece mounts or irons only), synthetic buttstock and forearm as possibilites to consider.
Aluminum in the rings/mounts makes some difference.
I have my doubts about drilling the buttstock really paying off. The type of forearm in wood has some weight advantage, ie going from standard beavertail to AH.
There has been some that removed the hanger, but quite a bit of work to do so.
By far the easiest is the barrel approach in my limited view. One could calculate roughly how much the payoff would be. Various barrel makers have taper/length/weight software for the surfers.
One might remember balance in the firearm. Putting on a #1 taper or featherweight barrel with AH forend, causes the rifle to be heavy in back with factory wood.