Each rifle will be its own beast. That's why best bet is to try it out and see what works best. What shoots in one person's may be completely different than yours. Generally speaking same Barrel length and rifle twist will affect it, but each rifle is unique. How many years have they been making that said model of rifle? Are they even made in the same plant as someone who may have bought the rifle say 10 years ago. Also the reamers that they put rifling in with become dull and worn down as they are used more. So first rifles may have tighter rifling than one made towards the end of the life of the reamer.

I would pick the rounds you want, and the size bullet and see how they shoot. Pick couple other boxes of the same bullet size out from different manufacturer or two and see how they shoot. Have fun and keep us posted how your range days go.

The .308 is more than adequate for any North American Big game other than the big bears with bullets from 150 to 180 grains, from up close to longer ranges than most of us prefer to shoot... 300 yards is perhaps a sensible limit, although the cartridge will cleanly kill big game at longer ranges..

If I were hunting deer and black bear with a .308, I would first try the cheaper factory loads, such as Remington green Coreloct and Winchester powerpoint and Federal whatever, and use whatever load from 150 to 180 grains that my rifle groups best...

The critters you shoot will never know the difference..

I have two black rifles (AR15s), both with the same rifling twist, and they don't quite put the same load to the same point of impact. So, generally, I'd suggest that you're quite likely to find differences between your rifle and someone else's identical rifle.

Although you'd like your rifle to group well, you don't need the same kind of precision when hunting that you do when target shooting. If you can hit a paper plate reliably at 100 yards from a standing position, then you're in the ballpark. Benchrests are not for hunting.

Get some ammo, go to the range and get comfortable with your new rifle, and I think you'll find all of this much simpler than you might ever have imagined.