We stock 2 3/4 #6 for upland birds, both 3 and 3 1/2 size 5 for turkey, 2 3/4 00 buck for self-defense, 1oz slugs for large game and oodles of 2 3/4 #9 for skeet. Now multiply this x2 as we have it all for both 12 and 20 gauge shotguns.
These are not .22's or even 5.56. You really don't need thousands of rounds of each except the skeet stuff - and we reload those. In a season we use maybe 1/2 box of Turkey loads, 6 of the upland bird, none of the 00, and maybe 1 -2 slugs, if we aren't using the .308...