Ruger M77 in 7mm Rem Mag. , has the versatility of the '06 with a wide range of loads down to 120gr, and up to 175gr.
As was said before, shot placement is EVERYTHING.

I would take my Encore in 35 Wheelen.

I would feel good about using most of what has been mentioned, especially the .300 Win Mag as the 30-06. My first choice would definitely be the .338 WM.

I don't know why sconnyhunter is being bashed for shot placement? I would suggest either the 7mm Rem Mag or the 300 Win Mag but if you cannot handle the recoil at the range or the higher prices of ammo then I would go with the famed 30.06. The first two are flatter shooting however and pack a little more puch then the last. That being said I owned all three. Started out with the 30.06, next went to the 7, and finally graduated to the 300. Now my plan is to keep the 300 and add a .308 and a .243.

I feel comfortable with my 300 Win Mag in a BIG bear situation or even a deadly Lion situation but if I were to hunt either of those I would opt to get a 350 Rem Mag. But since you stated for anything in NA disregard anything bigger than a 300 Win Mag.

Cheers

lots of practice on the range with the same rifle you will be hunting with ..my pet caliber is a .300 wsm with a good bonded cartridge 180 gr accubond ..

Because saying "shot placement is EVERYTHING" is the same as saying caliber is everything. If you believe that then why even recommend a cartridge/caliber because anyone that lives in that world either can't grasp their own understanding or doesn't believe in any one caliber is different than another.

Apples and Oranges, rather be huntin. Shot placement with any caliber is critical. No matter what the cartridge is if you hit the animal poorly you are in for a long track, or much worse a lost animal.
Yes, the choice of caliber is important, depending upon what game animal is being persued, however given that many of the calibers used today are so versatile, it matters little what is used and more where the bullet is placed to make a fast, clean kill.

I am very comfortable with the 7mm Ruger I posted about, as it is what I shoot. I know exactly where that bullet will strike everytime I squeeze the trigger. IMO, caliber is a personal choice for each hunter.

As a matter of ETHICS, shot placement is not. Shot placement IS EVERYTHING. We may agree to disagree, but, I believe that a poorly placed shot is among the worst things we can do as hunters.

I can see your point but one has to be comfortable with the weapon they are shooting as well. Yes, I do call it a weapon considering we are referring to dangerous game. Just to throw this out there I seen a hunting show where five hunters had HUGE caliber rifles and all of them fired at a charging line, mostly missing it but a couple of shots had hit the Lion in the sides. However the Lion continued to charge his chosen target but it wasn't until that last shot by the target square between the eyes at point blank range until the Lion had fell to his death on top of the targeted hunter. I've also seen another hunting show where someone dropped a very nice bull Elk at 380 yards with a .270 and a well placed shot.

line = Lion

Hands down a Remington 700 in 300 Win Mag.