I am a real believer in 165-grain bullets in .300 Savage, 308 Winchester, and the 30-06. I have mention earlier that when I was a kid there was a neighbor who was an Oregon, California, and Washington .30-Caliber champion. I first encountered the 165-grain Hornady on his reloading bench. If I recall correctly this was in the early 1960’s and IMR4350 was not on the market at the time. He was loading with IMR4064. More impressive then the trophies were the bucks hanging in his garage every year. I watched them skin out many a deer and I do not recall seeing a recovered bullet. The man was a competitive champion and I am sure he would not have used a bullet that did not produce good accuracy in his rifle. I spent enough time watching him load for his 30-06, and his varmint rifles to know that he was perfectionist. The man hunted in California and Oregon obtaining the maximum number of tags each year, and filling them.
As I grew a little older I acquired a friend who hunts with a 30-06, his favorite bullet is a Speer 165-bullet. Normally those bullets are not recovered, but one evening his bullet penetrated the top of a stump, entered the flank of a buck, and stop up against a front shoulder. I am guessing that weight retention was close to seventy percent, with jack and core together.
I have loaded the Hornady BT, flat base for the 30-06. The loads were accurate and good enough to qualify with the rifle. I have loaded 165-grain Remington C-L, Hornady BT and Flat base, Speer Hot Core, and Nosler PT in the 30-06, and bolt action .300 Savage. In either rifle the bullets stay in the same small group at 100-yards. In the 30-06 I used H414 and H4831 powder. If I did not have the other two powders I would have tried one of the 4350 powders.
I have hunted Mule deer for over 40-years and I see no need for the Nosler Partition or other premium bullets for them when using a 165-grain bullet out of the –06. The only reason I load and hunt with them is they were given to me. The 4x4 mule deer I shot this year hit the snow so fast that I was slight confused because I lost sight of the deer with the recoil. When I skinned the deer the rapid expansion of the bullet was obvious and then the path across the front of the shoulder, into the neck, hitting the spine and exiting out the other side. The amount of damage generated by the bullet before hitting the spine was impressive. I am sure that at 30-06 velocities a hit at the same location would generate complaints of to much meat damages from some hunters. This is typical of what I have seen with 165-grain bullets in the 30-06. I hunt in Black Bear country and I have seen a number bear take with 30-30 rifles up starting with 150-grain bullets. The 165-grain bullet is an improvement over a good thing.
Many will argue in favor of a 180-grain bullet in the 30-06. If you are into Texas Heart Shots it will offer you outstanding penetration, and break up the pelvis of a departing deer. While I will not argue against a 180-grain bullet, the 165-grain, .308-diameter bullet suits my needs when it comes to deer hunting.