Prison Planet (not one of my favorite sources -- or the most reliable -- as readers know) has an interesting article DHS Purchases 21.6 Million More Rounds of Ammunition." However, this one is sourced from this DHS solicitation for 21.6 million rounds for the new anti-terrorism center in Artesia NM.
As I read it, it looks like 21.6 million rounds to me, with the quantities ordered. For example, 100 quantity of 100,000 rounds for the first line item.
My first reaction is that is surely a nice ammo dump for DHS to conveniently stash 21.6 million rounds for the New Mexico militia and state authorities in the event of civil war.