Probably NO help, but in the 6.5 Grendel of mine, I use 29 grains of W 748 for bullet weights from 100 to 142 grains.
In the Grendel case I can't get enough W 748 into the case to cause over pressure issues.
Located this on a quick internet search:
https://forum.accurateshooter.com/threads/6-ppc-w-748.4121288/Three posts on the subject. They mention the charge as 27.5 to 29 grains of W 748 also.
I worked up the 29 grains on my Grendel ( Ruger American Predator ) on my own.
Small rifle primers used... case in the Grendel isn't that particular at all.