Sales Records: FFLs are required to maintain records of the acquisition and sale of firearms indefinitely.
The dealer must record, “in bound form,” the purchase or other acquisition of a firearm not later than the close of the next business day following the purchase or acquisition.
The dealer must similarly record the sale or other disposition of a firearm not later than seven days following the date of such transaction and retain Form 4473, the Firearms Transaction Record.
When a firearms business is discontinued, these records are delivered to the successor or, if none exists, to the Attorney General.
With very limited exceptions, records of firearm sales are not maintained at the federal level. The National Firearms Act Branch of ATF does maintain a limited registry of machine guns, short-barreled shotguns or rifles, and silencers, known as the National Firearms Registration and Transfer Record.
OK, so bottom line.
The feds do not keep records on all of our purchases.
But by requiring the dealer to keep his records forever, the information is there for the feds any time they want it.
The feds are getting what they want through the back door, thus avoiding the restrictions congress put on them.