I try to keep my firearms purchases in a few select popular calibers .40, .223, 12guage, 7.62 etc. I have compiled a LOT of ammo in these through the years.
In the last month I purchase the first .22 I ever owned in my life. I never saw any since in having one. In last two weeks I've bought two more 22s and 1000's of rounds of ammo. While you can't hardly find .223 around here 22 is everywhere and damn cheap. It's not my first choice for defense of course. But there are a lot of dead people that can testify to its effectiveness if shots are well placed.
I am now of the mindset that you can only shoot one handgun, shotgun, or rifle at a time. If you can't feed them ammo, they are useless. I stock higher levels for my primary carry and home defense tools. Less for my play toys. Keep your powder dry.
Yea though I walk through the valley of the shadow of death, I will fear no evil. My rod is a GLOCK and it comforts me