Grendel doesn't seem fussy at all to load for does it? Seems to shoot pretty well with a variety of bullets, or at least mine do. My go to hunting loads have been 120 sierra pro-hunters and 120 speer gold dots. This year I'm using 115 Barnes Tac-Tx. I've used the Tac-Tx in 300 blackout and it worked well. Just moving to lead free rounds for hunting.
I load for the Grendel. No issues. I also use the Sierra Pro Hunter in 120 grain and it's dropped everything in it's tracks.