From the National Shooting Sports Foundation:
NSSF is aware that Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) executed a search warrant at Polymer80’s offices in Arizona and seized from Polymer80 one “Buy, Build, Shoot” kit and some company records, apparently including customer lists for those kits.
According to several news reports, in the affidavit to obtain the search warrant – which was leaked to the media – the ATF took the position that the Polymer80 “Buy, Build Shoot” kit is a “firearm” because it is “readily convertible” to fire.
It does not appear that ATF considers standalone so-called “80% receivers” to be a “frame or receiver” regulated by the 1968 Gun Control Act. Retailers should consult with their attorney and/or contact ATF for guidance as to whether it may sell “Buy, Built and Shoot” kits and under what conditions. NSSF will continue to monitor this situation and report further as we learn more facts.