California has become the first place in the world where firearms must be fitted with highly controversial technology that stamps their serial number into every cartridge they fire.

The former legislator who introduced the bill said it “moves California to the forefront of the nation in combating gun crime” and other anti-gun lobbyists have welcomed it as the future of policing gun crime.

Police say the technology will help them solve crimes, but critics argue it is deeply flawed because it is too easy for criminals to subvert it.

“An independent, peer-reviewed study published in the professional scholarly journal for forensic firearms examiners proved that the concept of microstamping is unreliable and does not function as the patent holder claims,” Larry Keane, senior vice president of the National Shooting Sports Foundation, said.

“That study noted that microstamping can be easily defeated in mere seconds using common household tools and criminals could simply switch engraved firing pins for readily available unmarked spare parts, thereby circumventing the process.”

The Californian legislation attempts to solve the issue of swapping firing pins by requiring two imprints be made by every gun, and the breech face is one potential place it could be done, but such markings could be filed off.

The law applies to all new semi-automatic handguns approved for sale in the state, but does not affect those already on the approved list, nor revolvers or longarms.

The ready availability of non-stamping firearms, including anything purchased outside the state, make it highly unlikely that criminals would be foolish enough to use a microstamped gun unless it was stolen.

It has also been argued that criminals could plant a third party’s microstamped cases at a crime scene, effectively framing an innocent person.

Costs have been estimated at anywhere between 50c and $8.50 per gun, and Mr Keane said the industry would have to spend “astronomical sums of money” to tool up for the process.

New York legislators have tried and failed four times to have the same legislation passed there.

Keane described the NY bill as “extraordinarily dangerous” and said it “not only threatens law-abiding gun owners but our industry’s ability to supply the nation’s law enforcement officers and military with high-quality firearms”.

California’s legislation was approved in 2007 but only came into effect last week after patents on the technology expired. Gun rights lobbyists had tried but failed to extend the patent.

So far no gun maker has produced a firearm that will comply with the new Californian requirement.

The approved status of firearms on California’s list of legal guns expires after three years, meaning that unless manufacturers adopt microstamping in their production process, no new semi-automatic pistols will be available in California by 17 May, 2016.

The National Rifle Association sees the California legislation as a ban on firearms and therefore an attack on US Second Amendment rights, and the organisation intends to challenge the law in court.