First of all, please don't take me for an expert, that I am not. However, I've owned, loaded for, and hunted with 300 win mag(s) for more than 40 years and love the caliber. I bought my first Model 70 when I was 15 years old. Unfortunately, I possess the hearing loss in my right ear to prove it. Ear protection wasn't cool back then. The 300 win mag will work on about everything in North America, if pressed into service. I've taken everything from groundhogs to elk with it. At one time, I used 150's on deer and moved to 180's on larger animals. However, I have abandon the 150's in favor of the 180's as the norm and 200's for longer shots and larger game. Keep in mind that I rarely shoot beyond 300 yards, now. It is also important to keep in mind that very close shots with light bullets can be very destructive/explosive and may not penetrate as needed at velocities in excess of 3000 feet per second. Thus, if you are shooting the 150's or 165's, a well constructed bullet may work in your favor.
I shoot a lot of Barnes TSX bullets and more Woodleigh's. The Barnes TSX or the Woodleigh's have never failed me, both are accurate, expand properly, penetrate, and both retain excellent bullet weight. I have not had the same experience with the Barnes TTSX. Shot one elk at 300 yards broadside and lost it. No blood trail and no evidence it had ever been hit, other than staggering. Next, shot an elk twice at 100 yards or less in full run through chest. No expansion of bullets at 2900+ fps, either of which should have done the job. As you might expect, this turned out to be a very bad day. Elk was stopped by friend with 8mm Rem Mag loaded with Barnes TSX. The 8mm TSX cut a hole through as big as a quarter (as expected). Upon examination, the 30 caliber holes (TTSX) appeared as if steel jacketed bullets had passed through. I did find the Barnes TTSX to somewhat more accurate and that was the reason I was trying it. You may call me bias, but I am unconditionally/completely done with plastic tipped bullets on large game. If you hunt the western states or far north, you may also want to consider accidently surprising a large predator that may necessitate a bit more bullet weight.
I don't find compressed loads very appealing for hunting, since you may encounter extreme variations in temperature (pressure) and ignition issues. However, they may work fine for you. To each their own.
My pet load that has worked in all but one of the 300 win mags that I have owned is:
Remington or Nosler (now available and more consistent) brass
Brass properly trimmed, sized, and prepped to industry standards
72 grains Reloader 22 or RL 23 (tried it during heat of summer)
180 grain Barnes TSX or 180 grain Woodleigh
(consult Barnes and Woodleigh manuals before loading)
Bullet set off the lands to suit your rifles chamber and magazine length
CCI Magnum Primer
Seal the primer for adverse weather!
I hope that this helps.
