Lol - not sure about those. Know they always used proper 8 ROT in 6.5s...

Had an older 77V long ago, tang model, 6mm, IIRC it was 9 ROT, put 5 97gr Hammett VLDs into one hole using old H450, 1x neck sized Fed brass, and match primer. Don't think the old Rem 244 12" would spin that.