One rifle for North American big game?

[Luvthunt]

I know you asked for one gun, however your range of animals and area beg for two. My choice for Fla. would be a Marlin guide gun in 45-70. The other would be a 300 Win mag because you may be in grizz country. Either one could back up the other in the right circumstances. Other then that a 338 win mag

 

[colorado]

500 Jeffery, "they don't get up"

 

[Forrest Halley]

500 Jeffery, "they don't get up"

That sure is a beautiful rifle sir. I realize that your immense love for it makes you suggest that it could be the one rifle for all North American big game.
I wonder, in light of this post and its clear power curve, if we shouldn't amend this question?

How about what is the largest rifle for North American big game that is still easily sustainable? How far down do we drop in the power curve there?
By sustainable, I mean I can go to a store locally and purchase loaded ammunition ideally and if not at least purchase components. I'll bet this drives it down well below .458 in a lot of places. Around my home I can drive to a store locally and get up to .338 just about everywhere. Some .458 light weight projectiles are available and some loaded .45-70, but .375 is not easily found loads or otherwise nor is .458WM/Lott. I'll bet it's a .300 or .338 WM for most places.

 

[colorado]

I would say if you're young, recoil sensitive and immortal a 270 Win with 150g Partitions at 2900 to 3000 fps would do the trick for everything including brown bear. It's what I used for a long time including a couple of dozen elk, many deer, 9 bears (finishing shots on two grizzlies in the thick stuff when I was a guide in my 20s). Next step up the 30-06, then the 300 Win Mag. After that I would go straight to a 375 H&H in a light rifle (ours weighs 7 1/2 lbs with scope).