10s of thousands fit in a few cubic feet.
I just weighed roughly a cubic foot of 9mm, which should be close to 0.22 in weight/volume if not worth, at 60 pounds. At about $500, that’s $8.31/lb, or 6 tons per $100,000 (vs less than 6lbs of gold to store the same value). I don’t know the relative cost of 0.22 vs 9mm, but with gold coming in at 2,000 times better as a store of value in large quantity than 9mm, I’m thinking it’ll beat 0.22 pretty easily as well.