Good information. I store ammo in similar containers. I have some metal Cal.50 cans. Most of them are plastic, whatever is on sale at Cabelas, MidwayUSA or the Sportsman’s Guide. Other than a few thousand round cans of .223 REM, all my cans are a mixture of my different weapons systems. I also put a few magazines and speed loaders in at least one container per storage location. I did learn something here. I place the silica packs in all my cans, but did not know when they are spent. Four months is a good time to start rotating. Word to the wise: If you put the silica packets in the oven to dry and reuse, keep an eye on them. Most of mine melted on the baking sheet, even though I set the oven lower than recommended and checked on them way before the instructions said to pull them out.
I strongly disagree with using a dessicant in small arms ammo storage cans. If you remember, the military does not use dessicants for small arms ammo. The dessicant will slowly pull water out of the primers and powder. This is not a good idea. It will change the characteristics of primer ignition and powder burn rates. Don’t do it. I have opened many military cans, including US, Russian, German, English, And Greek. NONE OF THEM HAVE DESSICANTS IN THEM.