I probably should have conditioned that on every ammo purchase using plastic. It would be easy to record ammo purchases on a card because I believe the NSA archives every electronic purchase any and everyone makes as part of their banking monitoring. Later on a simple database query to list all purchases of ammo for a certain time period would not be hard at all.
That wouldn't surprise me a bit, even if the Nasty Snooping A$$holes aren't monitoring closely, since their crony banks are in cahoots with them in their plans to rule us, and would gladly give them the transaction info, especially from places that primarily deal in that kind of stuff.