You worry that some government entity is going to sift through every debit or credit card transaction looking for ammo purchases? They are going to every sporting goods store in the US looking for the names of people who buy one box of .38 S&W? If they look at my debit card transactions they will only see the retailer and amount. It will not tell anyone whether it is ammo or fishing bait. The US government who cannot manage Medicaid can also collect data on ammunition purchases from everyone? It is the fallacy of “perfect government” where they can only perform nefarious conspiracies efficiently.
Again, Tennessee is one of those “gun friendly” states where a separate record of ammo purchases are not kept.