You might get more info if you edit and add the caliber and bullet into your title.
I don’t have your answer, not having loaded for this round, but if 59 grains was good for 147s, you might drop down a couple grains and work up to 62 or so by .5 increments. It’s fairly typical that you can use more powder for a lighter bullet in the same cartridge, but you do not know exactly where the person using 59 grains was regarding pressure. Nor what brass, etc.