180gr is an excellent all around bullet weight in the 300 Win mag.I've never used the 150gr in the 300 Win Mag,I'm sure they will kill stuff but,it would not be my choice unless it was a mono or a bonded bullet.Something that's often not to talked about is sectional density. Bullet construction is a bigger factor,but if you look at the most popular bullet weights for game bullets,a sectional density of around .250 or higher seems to be the most used weights for hunting bullets.
https://www.chuckhawks.com/sd.htm

~Molɔ̀ːn Labé Skýla~
As Bob Hagel would say"You should not use a rifle that will kill an animal when everything goes right; you should use one that will do the job when everything goes wrong."Good words of wisdom...............