Since I buy .22 rimfore target om 10,000 round lots (minimum) there is at least that much around.
For .45 ACP, .38 Super Comp, and other pistols 1,000 rounds a week is routine. There are at least 5,000 of each ready to go.
The varmint rifle gets a lesser workout (and takes a lot longer to load) so I only have a few hundred rounds of .22-250 AI and 6mm Rem AI most of the time. O do have two rifles for .223, so there are at least 5,000 rounds loaded most of the time.
.50-70 brass runs almost $3 per shell, so i only own 200 shells. .45-70 is for fun (and cheaper) so I think I have 500 or so.
Other calibers in lesser amounts, including .30-06, .221 Fireball, .45 win mag, .357 Mag (including a lot of .357 brass loaded with 148 HBWC).
I never considered it was possible to have too much ammunition.