I was mainly using the GM762M2 years ago and never had an accuracy issue. Most of the dope and experiences you will see in credible places speaks highly of its accuracy.
However I did switch to the GM308M (168 BTHP) based on a Lightfighter's recommendation. it has the same muzzle velocity and the accuracy is pretty extraordinary at the distances I shoot (=457 meters).
I believe there are some older threads with B. Moran and others that went though this. It was also on Doc's .308 duty rounds list, which I can't find.
I was using ADI 168gn SMK but found issues at 900m+
The rounds perform ...the case tarnishing on 5 year old rounds had me wondering if this was normal for the round or a sign of storage issues.