Wrong. ATF final rule 2021R-08F classifies AR style pistols with a brace as SBRs. SBRs are also NFA firearms, and NFA firearms have been regulated by the federal government since the National Firearms Act of 1934. The law prohibiting the transfer of unregistered NFA weapons can be found here, Chapter 9, section 9.2 of the National Firearms Act handbook:What he is saying is the rule that is turning AR pistols is their "new rule", it's not a law. Yet.