Are we going to BAN Hardware Stores and Drill Presses too??
http://thehomegunsmith.com/pdf/9mmPistol.pdf
http://www.replicaplans.com/BlueprintDownloads/Expedient-Homemade-Firearms-Vol-II-PA-Luty.pdf
https://www.amazon.com/expedient-homemade-firearms/s?k=expedient+homemade+firearms
Back around 1970, Guns and Ammo magazine had an article about hand made guns built behind California Prison walls. Even the ammo was hand made.
One shown was a fully auto sub machine gun. Crude but it worked.