How much money would it take to buy the platform and 5,000 rounds?
I suspect the answer to that questions will also answer whether this is a better SHTF weapon.
I’m considering changing from .308 to .223 just based on ammo availability and price.
You can never go wrong on 30-06.
If long range is only object? 300 Win Mag is a great common cartridge.
30 caliber bullets? super available. Even cast lead with gas check will work for 30-30, 30-06, .308 in a pinch.
I do reload and cast bullets. I’m cheap.