165 GK according to Sierra H4350 58.6 - 67. As usual start at the bottom and work up. Monos will usually hit pressure before cup and core. I can’t even begin to say why you had sticky extraction, but I do have 3 rifles that are tight, match chambered and all 3 had higher velocity per charge from the manuals, but then I never work up a load without a chrono. No Chrono means no facts which means just a guess.
