In President Joe Biden's address to Congress tonight, he repeated his intention to, in a manner still unspecified, ban so-called "ghost guns" made from kits that have no serial numbers and which you can buy without the background checks required in buying assembled guns from licensed dealers.
In a recent Reason TV video, Cody Wilson, a major entrepreneur in this currently legal space with Defense Distributed, guesses that the method Biden will go for is requiring serialization and background check for buying more of the component parts that go into making these finished homemade weapons.
This would mean that people dedicated to anonymously making homemade guns would have a harder time acquiring materials, yet the proliferation of home milling tools and software to guide them means that while Biden might be able to make home fabricating harder and more expensive (depending on the price of aluminum blocks), he cannot eliminate it. At a certain point, the feds could complicate the homemade scene such that people go back to just buying on the black market, which is stocked with non-homemade weapons.
California is ahead of Biden's game in banning ghost guns, having since 2018, as the Center for American Progress summed up, "require[d] all self-assembled firearms to contain a unique serial number from the California Department of Justice. Furthermore, owners of newly serialized firearms must provide identification information to the California Department of Justice. Under California law, self-assembled firearms cannot be sold or transferred."
At the same time, California has remained a place media calls on to scare you about the still growing threat of ghost guns, such as the claim made to ABC News last year by Carlos A. Canino, the special agent in charge of the A.T.F. Los Angeles field division, that "Forty-one percent, so almost half our cases we're coming across, are these 'ghost guns." Last year was two years after California banned them in just the way Biden plans to. Not a promising sign for the efficacy of his bold initiative.
Various cities have reported scary-sounding percentage increases in captured ghost guns in the past few years as the hobby has spread, though, again, one could eliminate every homemade gun and still have plenty of traditional firearms to go around for both crooks and peaceful citizens. As J.D. Tuccille and Jacob Sullum have argued at Reason, Biden's effort might make life harder on hobbyists and conceivably make punishing someone for a crime already committed easier in some marginal cases, but it can't possibly be expected to make a serious dent in overall gun violence. Likely its only real goal is to satisfy some of Biden's political constituents.