I don't shoot a .300 Magum, but maybe my experience will help. My sons and I shoot a lot of 168 Matchkings in .308 or .30-06 when we're doing load development. Once we settle on a load, it's an easy task to move to a 165/168 hunting bullet. I normally use either Gamekings or Hornady bullets for hunting. I find that the point of impact is really close. I'll fine-tune the hunting rifle in the late summer, but generally switching from target bullets to hunting bullets only requires a couple of clicks one way or the other.
What do those of you who shoot this caliber use for a hunting bullet
That's a whole 'nuther question, and one that you'll have to decide for yourself. There are lots of great hunting bullets in .30 caliber, some expensive, some less expensive. There are monolithic bullets, bonded bullets, standard bullets, Partition type bullets, and the choice is all dependent on the game, the range, and what your personal preferences might be. But, as long as you stick with one weight bullet for practice and use that same weight bullet for hunting, you'll find that the rifle generally shoots fairly close to the same point of impact.