Welcome aboard, djs! Glad to have you join us!
Actually, this is a challenge all of us face. Most, in time, find or make a suitable cabinet. I’ve seen dental office cabinets, map and print file cabinets, printer’s cabinets, spool (as in sewing) chests and many varieties of made-to-order articles.
Personally, I’ve contacted several manufacturers to ask if they would consider a custom order to produce some metal cabinets to specification. No bites.
Many years ago, one of the major cartridge dealers of the time took on a franchise to sell the perfect cabinet for our needs (made for small maps); he had dozens of them to house his own extensive collection and man, they were nice! I kept putting it on the back burner because they were pretty darn expensive even though I could have picked it up and saved the freight (which can add enormously to the price). That’s one of the things I would change in my life if I had a time machine.
If you look down further on previous topics:
these will also give you some ideas.
The one thing I would emphasize is that if you have any caseless rounds, get 'em out of those plastic bags!