In .30 caliber, 150gr and up are considered deer and big game bullets. 150s, 165s and 180s are the most commonly used for deer. Any hunting load in these weights from a quality manufacturer will do the job well.
The key is how well you can do the job with your rifle and ammo combination. Rifles are individuals, and some are really individual. Each one has its own quirks when it comes to what ammo it shoots best, and worst.
A "good" rifle won't show a lot of difference between its best and worst, but if it does, its not the end of the world. You just use what it likes (within the class of ammo suitable for the task) and avoid what it doesn't.
Most often a rifle will have a different point of impact for different bullet weights. Sometimes they will show a different point of impact between different brands of ammo of the same weight. These are things you need to know, before going afield. And they are only found out by shooting.
Buy a box of each of the available brands and weights. You don't have to do it all at once. Shoot some brand A, 150s and see how they do. Then try brand B, C, etc. the next time. If one is more accurate than the other by a significant amount, use it for hunting.
Next time try a different weight, going through the brands, as time and funds allow, Eventually you will find the brand and weight that shoots best in your gun. What I am trying to say is that say you have your rifle dialed in for Rem 150gr corelokts, but when you go get shells for your hunt, all they have is Win 180s. Finding out that they print 3 inches left and an inch low from where you are sighted in with the Rem ammo, (for example) might be a vital thing when you line up on a deer at distance.
