It looks like their goal is to buy the ammo off the market and then anyone wishing to purchase it has to go through their contract/issue process in order to get it. This is not just a restriction on civilian sales/purchases, but a restriction on other government agencies, just in case they don't want to be going along with DHS programs, they don't get any ammo. That's how they will be keeping any rogue national guard or police units in line.

The practice has been done by higher level government against the National Guard for decades, since they always knew the National Guard was made up mainly of patriots (hardly anyone is there for the money). It is not exactly "disarmament" but "selective armament". Lenin would be proud, very proud.