By Golly, I have a lot of FA 1934 rifle ammo. (Federal Arsenal. National Match ammo from Camp Perry matches.)
Lord only knows what extremes it had been through.
Most recently I went through a campaign to disassemble it and change the mercuric primers for new non-corrosive primers.
As a matter of course, I also reamed the primer pockets, mildly chamfered the inside of the necks, and polished the cases and bullets.
I reassembled them with precisely weighed the powder charges. (Which I had found to be very precise anyway.)
Last step was a very mild neck crimp into the relieved partition on the bullets.
Random checks found the components to be very precise and I mean +/- zero on my scale. (1/10 grain accuracy gradients.)
I've never found any of it to be lacking in ability or accuracy. (173 grain FMJ BT bullets.)
I also have .45ACP from the same era that is fully viable.
It hasn't gotten carried around in a truck or car routinely, but storage has been in non-controlled environments. Dry places, original boxes, original cases.
So I'm a bit surprised at ammo rotation routines.
Ignorance is bliss... I guess.