Huh? Where'd that imagination come from? Is it the case today that one can only buy ammo at walmart? No. What indicates to you that for some heretofor unknown reason, ammunition will be available only at walmart... and this due to the implementation of a nrst... and sunspots no doubt???
What the hell kind of sense does that comment make?
Now imagine that there are controls to prevent this. I can't imagine any such controls but maybe your imagination is better than mine. Now imagine I want to buy a whole lot of ammunition. I am willing to pay sales tax. How will I be able to purchase that ammo anonymously?