The 7 P's comes into play as well. All of my pistols use the same caliber bullet (different cartridges) but I plan far ahead so there is no need to have multiple calibers which limits economy of scale.Let me also add that having firearms in a variety of calibers is a way to mitigate this crisis.
The current situation has repeated itself at least 5 times since 1993 (in a big way) so we should be able to recognize the signs before it happens and plan accordingly. The plan should include factory and reloaded ammunition and components to reload the same as well as N+2 replacement parts for all weapons considered critical or important.
But, hey, that is just me.