I'm at 40. All the common ones for pistol and rifle, plus a few oddball/obsolete calibers. I have at least some ammo in stock for about 35 of those.
.22lr
38/357
45acp
9mm
Rifles.
223
308
30-06
12ga
Don't need any more
ZGrand, 303 British doesn't fit with that list. Is there a story there?