I use plain old .308 for everything in North America.
Like yourself - I'm just about ready to totally convert all of my ballistic commitments to the time-honored .308 Win.
However, I started back in 1965 with the then-new 6.5mm Remington Magnum with a 3-9X Bushnell, and made it into a short-barreled tack-driver with 87gr match HPs. I shot everything from groundhogs to deer to ants out West. It was a one-shot-one-kill with either the 87 gr or the factory 120 gr. An ant at 385-paces was my 1960s longest.
By 1967 I'd added a .22-250 Remington Mod 700 HB, topped with a 12X Redfield, and tuned the 52-53 gr match BTHPs into 0.50"dia. groups. During the late 1960s I took three buck deer with single neck shots.
Then came the 1980s and I'd tuned a 3,000 fps .270 Win into a one-gun-out-West caliber, taking ants, elk, and mule deer with 130 gr bronze point hand loads.
Buy the early-1990s I had two 300 Win Mags, one a very accurate M1000 Browning, but found after several seasons that I was working harder by carrying more weight, for the same degree of success and a bigger "Boom!" afield.
Then one day a friend who shot high-dollar live pigeons with a very pricey Perazzi, and I were shooting trap. I had my oldest Winchester Mod 12 Heavy Duck and was a few birds behind. I told him that perhaps, if I upgraded my shotgun to his level of investment - I might be better competition?
He looked at me, and laughed! Then he plainly said:
"It's not what you shoot, but WHERE YOU HIT! - that matters." (Like I was some kind of idiot, and to some extent he was right. I'd never thought of shooting in those terms.)
Later he explained that
"confidence" was the largest part of is his mental shooting game, and that weighed more than anything else on his ability to be successful! He said he began by shooting a Remington 1100, that a local gunsmith had tuned and fitted to him. And it shot just as well for him, but as he had become more financially successful, he felt like he had to keep up with the other shooters, so he ordered himself a - custom Perazzi.
"...but I still shoot that 1100 when bird hunting," he confided.
So now days - I have a sub-MOA .22-250 Rem that is about broken in for our young daughter (She's mastering trigger-pull with a target .22 with a short stock and a bull barrel right now.). And I have a same-make-n-model, MOA .308 Win for our collective use if that becomes necessary.
The two older boys now have
all of the other-and-larger-caliber rifles and most of the shotguns. So I'm focused on the .308 Win most days, from the shooting bench on the patio. And to it, I am both confident & committed that I can
"hit" where I aim.
Oh sure, there is a like-new Remington 700 chambered in 7mm STW in the closet, waiting on a riflescope, along with maybe 10-boxes of factory 140 gr ammo. But I don't really have any personal
"confidence" in that rifle...yet.
My point here - In case some may have missed it, is: The best rifle caliber for you, is the one in which you have founded the most -
"confidence"! And that is developed through, practice, practice, practice...
