I guess I should add that even though I said 300 WM earlier, and own one, I grab my 7x57 for everything down here in the lower 48. If Alaska / Western Canada was in the equation the 300 may get to go, but only if the big bears were on the menu.
Quoted from an Alaskan guide, “when your hunting deer, elk, or moose it’s fine to carry your 243, 270, or 7mm-08; but when you come across that brown bear you weren’t hunting the ballgame just changed”. The guide recommended 300 Remington ultramag 200 grain at least. I myself am switching to300 win mag 165 gmx hornady full bore for elk. Although I do have a 270 for whitetail if I feel like it. 30 caliber is a very reliable bullet. Lots of choices out there but if I’m in the mountains; I’ll have my 300 win mag. Bow hunting; I’ll have my bear spray and 44 magnum with 300 buffalo bore cast bullets. Great thread and great comments. Thanks for sharing .
Looking at the question the OP posted I would say .270 Win, 30-06 or .308. Primarily because the ease of finding ammo and the reasonable recoil from these calibers.. They all would get the job done working within the parameters posted.. Magnum overkill is overrated IMHO..
If I had to choose one caliber I’d personally choose 28 Caliber (7mm for the metric types). I’d choose 280 AI or 7mm-08 because they are both a little off the beaten path but in reality a 7RM is probably the most versatile choice in this caliber. When you figure that you can get factory produced reduced recoil ammo that ballistically matches the 7mm-08 or go for full power loads that’ll probably net you can extra 150-200+ yards of killing range depending on bullet design. It’s a versatile combination for the eastern woods, southwestern and midwestern plains hunter or the big west hunter.
Now the other options to realistically consider are the 30-06 and 308... and 300WM by extension (if you want to deal with more recoil). Plenty of great options and not a whole lot that you’ll be left wanting for.
If i had one i would choose a .308 I have taken coyotes, fox not the best for fox or yotes. But i have taken elk 800 yards with it and dropped him. I would have to say though the best gun is the one you are most comfortable and confident in. I know my 308 very well i do reload but factory ammo shoots very well also. For deer i use 125 gr and 162 grain on the elk. Bear i used the 125 grain also. I have shot this caliber since i was around 12 or 13 so 20years experience with the caliber and its capabilities. Moose never had the chance i live in nm but if i ever did i would shoot maybe 180grain rounds. If you want the best most versatile weapon just get a bow can hunt everything with one. Good luck with your choice whatever you get. I shoot a howa axiom 308 and wouldnt sell that thing love it. I also shot a tc dimension bolt action very cool and super easy to carry multiple platforms with not much added weight.