Variations of this discussion are Eternal , for good reason . But alas ; they all come down to parameters and priorities .
To what extent pure survival in rural to wilderness environment vs armed engagements with packs of thugs or quasi paramilitary groups ?
Persevere for a few months vs disappear into the sunset forever and ever ? ( Hint - The closer it get to living off the land forever , the better a single shot .22LR rifle and 10 bricks of ammo looks .)
IF ammo availability is a prime factor for you , Workman's list needs trimming in 2025 .
.30-06 and .30-30 are no longer common on local shelves . .308 has displaced them .
As much as l still favor the Classic Answer of 4 inch .357 Mag as the one handgun to have for everything , local ammo availability is at best on par with .40S&W .
Two Wild Cards :
When ammo buying panics start , the popular calibers ( that everybody else bought to "simplify their ammo requirements " are the first ones to immeadately be cleaned off the shelves . While .357 Sig , 10mm , and .41 Mag will languish for months .
Firearms enthusiasts such as board members here , are more likely to have stacks of their favorite calibers waiting in their ammo stash at home .