I've had no problem finding 7.5 Swiss and 9x18. I don't have much that shoots it, but I can shoot what I do have until the barrels melt.
I sadly only have one .22LR, and it's a breakdown survival rifle. I want to buy a 10/22 or something of the like, but they're hard to come by.
I’ve owned some pretty “outside the mainstream” calibers over the years, but in the last 5-10, I’ve tried to pare things down for some degree of standardization. Right now, about the most “exotic” chambering I need to feed is 10mm, which has always leaned toward the expensive side, but thus far, where I’m at, can still be found on some store shelves.