The ever vigilant FoxNews panders to its RW audience and the gun lobby by fearmongering on an issue that will clearly fail for all concerned. In the above example from a NGC documentary filmed in California, the "ghost gun" was used in multiple crimes and transferred multiple times.
California's gun laws are among the nation's strictest, but a looming decision in a federal lawsuit could effectively ban handguns altogether in the Golden State, according to plaintiffs who want a judge to toss out a state law requiring all new handguns to be equipped with technology that "stamps" each shell casing with a traceable mark.
The problem with the “microstamping” law, which was signed into law by then-Gov. Arnold Schwarzenegger in 2007 but only took effect in 2013, is that it relies on an unworkable technology, according to gun manufacturers and attorneys for the Second Amendment Foundation and Calguns Foundation. If guns without the technology can't be sold in California, and gun manufacturers can't implement the technology, the law is, for practical purposes, a handgun ban that violates the Second Amendment, goes the argument.

The law, the first of its kind in the nation, requires gunmakers to engrave the serial number in the gun's chamber so that it becomes stamped on each bullet as it is fired, allowing police to identify a weapon from cartridges found at a crime scene. Backed by law enforcement groups, it was passed in 2007 but took effect only last May, when Attorney General Kamala Harris certified that the needed technology was available and a private patent had expired.
Gun advocates immediately declared that the law was pointless because the technology was ineffectual and no manufacturers would comply. Eight months later, they're doing their best to turn their prediction into reality...
The law does not apply to semiautomatics that were already on the state's list of safe weapons approved for sale as of May, but only to new models submitted for approval since then. No manufacturer has yet produced a micro-stamped pistol for sale in California, and two companies, Ruger and Smith & Wesson, have announced that they won't even try.
Note first that it is paramount that given the numbers of firearms available in the US, there is a necessity for increased regulation of firearms for public safety whether as training, background checking and controls over sales and transfer with serious revision of many laws.
Recent terror events in Europe have shown how even modern democratic countries with reasonable gun control laws cannot stop certain types of firearms violence. Sensible regulation has as much rhetorical meaning as responsible ownership when industrial capitalism plays politics without considering the reality of a generally diminished mass understanding of how gun use actually occurs.
However, trying to create something that stamps rounds is simply creating a technology easily defeated and has as much deterrent value for homicides as the V-Chip has to constrain violent television content.
There are simply better technological and regulatory solutions and regulation must transcend the piecemeal approaches including for example the byzantine approach to defining illegal weapons by easily detachable accessories.
Without going too far into the concept of "unworkable", this bit of regulation while perhaps useful for some forensic investigation like tagging gunpowder is an attempt not unlike California's vanguard regional regulation of automobile emissions via air quality standards to regulate an entire class of commodities.
The problem ultimately is that the automobile-firearms regulatory analogy only works with those who will truly comply with the law and not attempt to bypass it. Criminals and scofflaws will bypass it. Not unlike the grey-market pipes meant to bypass the catalytic converter, there are too many ways to work around such regulations, including transporting weapons from other states not willing to play along.
This Californian bought his two banned Tec-9s in Nevada
There is no proportional reason to attempt a wholesale ban on handguns that cannot be properly regulated due to the volume of preexisting guns being available and there is no reason to even mention Constitutional Amendments since it is more about commerce than individual rights. The problem in the discourse is that it is led by an industry more worried about profits and lobbying than actual civilian safety.
Eventually, there will be a manufacturer who will use the patent license and make a sizable profit in California - just imagine to whom those profits will go.