Re: looking for lr advice
With a 308, & 168's I'd first suggest running your load through a ballistic calculator, assuming you haven't already, & see where it goes trans sonic. Then the next chance you get set up a target a couple hundred yds farther than that, & make sure the bullet remains stable through the transition. it will either stay on course, or it will tumble, & drop out of the sky. should be easy to tell the difference.
As I shoot 225's in a 300WM I have no experience with the 168 VLD, but I know the 168 SMK will tumble as reported by many HP shooters. If it won't transition you need to go with a 175ish, or heavier, &/or get a bigger cartridge.
You might get a reply from some one who has had the 168 VLD beyond SS range who can tell you whether it will work or not.