California Democrats are pushing legislation to require background checks for gun barrel purchases, effectively taking the “ghost gun” regulatory push to its logical conclusion. The bill, Senate Bill 704, is sponsored by state Sen. Jesse Arreguín (D). SB 704 singles out firearm barrels among the many other parts of firearm, requiring a background check for any replacement barrel or aftermarket barrel upgrade purchase. […] Moreover, SB 704 specifically outlines how the costs of performing background checks for barrels must be handled, making clear that the legislation literally creates “a new crime,” albeit a misdemeanor, in the state California. …