I'll go with the 30-06 for versatility.It has killed all land animals , including the African
big 4 (thank you Teddy Roosevelt) With adapters you can use .32 auto for small game
or .308 in a pinch.
.308, because a .223 might expand, but a .308 will never shrink.
In all seriousness, is there an application where a .22 or .223 will do the job but a .308 won't?
Are there any applications where a .308 will do the job but a .22 or .223 won't? I don't think there are for that last one. It's just a question of how many rounds you need to carry versus the weight of the ammo and firearm.
Im glad to see at least a few votes for .243. I am not sure why more .308 fans do not give this caliber a second look (except for ammo cost). It is as close to a do-all as Ive ever seen. It has more velocity, slugs from 55gr to 110gr, same casehead size and length as a .308, inherently tighter groups, and less recoil. If it werent for ammo cost, Id chamber my FAL in it or an AR10 (yes I know Remington has already done this). If I was using a bolt gun and not carrying as much ammo, possibly reloading a bunch, Id take a 243 any day of the week.
If we're just pickin to pick, I'll take a nice little Anschutz 54 sporter in .22 lr.
If we have an ugly situation in mind to pick for, prolly the .243. And a wide selection of bullets.
It's not a bad excercise, really. SHTF scenario and you have to bug out permanently and travel on foot, how many guns and how much ammo are you willing to pack? Little red wagon full of reloading components?
I'm going with .270 Win, because (1) I already own one (2) you can find ammo anywhere, and while everybody else is going for the 30-06 and .308 it should be more readily available (plus if you're out west - MT, WY, SD, not CA you can probably find it in most gas stations/hardware stores) , and (3) like the 30-06 it'll take down just about anything.