Agree with all those saying "whaaaa????" to the numbers. Just looking through the brass piles, there is VERY little steel cased 5.56 (for example) at the several ranges I frequent. Like... 1% of the cases left behind (and there's a LOT of brass left on the ground so there's not obviously survivorship bias at work here). Also comports with what is in people's bags when I am at club matches, walk down the line, etc. 9 mm? I'll see a handful of steel cases once a year. 7.62x39? Sure. Makarov, 54R, etc? Sure. But western cartridges? Naw.
There will have to be parts of the country where they shoot nothing but russian 5.56 and 9 to make up for those numbers. I want to see the math on that.