+1 on the lack of 22....didn't see any at local Walmart for almost a year, Cabelas was sold out of bulk packs for 3-4 months...but usually had minimag.
Most available round here; 25ACP, 357sig or occasionally 40.
But my question would be why you'd want what was obviously the least preferred of all calibers? Personally I'm not choosing calibers based on what the majority doesn't want! There's a reason they're not popular!