Federal law explicitly prohibits the creation of a federal firearm registry, but the Biden Administration has put together a national registry with almost One Billion transactions

In total, ATF manages 920,664,765 OBR (Out of Business Records) as of November 2021. This includes digital and an estimated number of hard copy records that are awaiting image conversion. It is currently
estimated that 865,787,086 of those records are in digitalized format.

The Biden Administration has not only been collecting and digitizing out-of-business records for licensed gun dealers, but Bank of America (BoA) also provided the FBI transactions with a BoA credit or debit card so that they could track purchases. It also is why gun control advocates push for universal background checks.

We have discussed many times how gun registries do not help solve crime. In theory, if criminals leave registered guns at a crime scene, the serial numbers can be used to trace the weapons back to the perpetrators. But, in real life, guns are only left at the scene of a crime when gunmen have been seriously injured or killed. With both the criminal and the weapon present at a scene, police can solve these crimes without registration. In the exceedingly unusual instances where registered guns are left at the scene, they aren’t registered to the person who committed the crime.

Police in Hawaii, Illinois, Pennsylvania, and New York have had registration systems in place for decades but can’t point to any crimes that this has helped them to solve. Even entire countries such as Canada haven’t had success. 

New York and Maryland spent tens of millions of dollars compiling a computer database that contained the unique ballistic “fingerprints” of each new gun sold over a 15-year period. Even these states, which strongly favor gun control, eventually abolished their systems because they never solved a single crime.

The only thing that gun registries are useful for is gun confiscation.

Federal law explicitly prohibits the creation of a federal firearm registry, but the Biden administration thinks it can circumvent those restrictions: as long as it doesn’t actually use the registry, it is OK to put one together. Presumably, they think the registry will be available for use once Democrats control Congress and the presidency and can change the law.