Max range for any practical weapon is the range you can put 4 out of 5 shots into a 6" target.
So Max Range varies according to conditions. Power has something to do with things too, but most hunting rifles have enough to get the job done The 375 H&H has WAAAAY more range than most men can use.
So it's mostly all about the man, not the weapon.

I once killed a moose Waaaaaaaaay out there, with a 375 H&H, but I had a perfect set-up and I used to shoot 1000 yd matches a lot, so I knew I would hit him, and I did.

I have guided hunters in the past who owned rifles set up for long range, who's max range was about 25 yds. I also know a man in Nevada who can (and does) kill deer on a regular basis at 350 to 500 yds with an iron sighted rifle, and as of 2 years ago, he's yet to miss one. He's in his 50s now, and he's been hunting since he was about 10.

As in most thing in this world, it's 98% the man and 2% what he's using.