Federal Review Finds Microstamping Technology Isn’t Reliable
In a letter to Congress, a federal agency concluded that microstamping does not produce repeatable, legible codes.
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States attempting to require the use of microstamping just hit a snag after a government agency revealed the technology isn’t ready for prime time.
The National Institute of Standards and Technology, an agency within the Commerce Department, sent a letter to Chairman Brian Babin (R-Texas) of the U.S. House of Representatives Committee on Science, Space and Technology earlier this month regarding microstamping technology. The seven-page letter dated August 12 and signed by NIST Deputy Director Craig Burkhardt, responded to a request Babin made in February asking the agency to evaluate the "true capabilities and limitations of microstamping technology."
Though NIST noted that it had not done any independent testing itself, the agency did review data in existing studies. Ultimately, NIST concluded that microstamping does not produce repeatable, legible codes.
In the letter, NIST noted that residue from gunpowder can accumulate in a microscopic laser-engraved microstamp, sometimes obscuring the code. This, in turn, makes the code illegible. Researchers also noted that legibility of the code is influenced by the firearm’s model, firing pin shape, and even ammunition fired. Altogether, NIST concluded that the data shows a history of inconsistency.
“There is significant disagreement regarding the viability of this technology,” the letter reads.
“Key areas of disagreement or concern include the long-term durability of the microstamps after repeat firings under various maintenance conditions, the dependence of mark transfer fidelity on the firearm-ammunition combination, the need to test a broader range of firearm-ammunition combinations, the high susceptibility to deliberate tampering, and the substantial costs associated with manufacturing mandates and necessary database management.”
Microstamping was introduced as a way to track firearms. In theory, a gun would stamp a unique code onto an cartridge case each time it fires. This would allow law enforcement who recover a spent case at crime scenes to trace it back to a specific firearm. In the roughly 20 years since research began, though, the technology has struggled to deliver on that promise.
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A 2006 study by Suffolk County Crime Lab firearms examiner George Krivosta published in the Association of Firearms and Toolmarks Examiners Journal found that full, legible eight-character code was recovered on only 54% of tested cases across 10 models. Nearly two decades later, a New Jersey Attorney General’s office test told a similar story. An armored fired 10 handguns and examined 10 cases. Only one produced a complete alphanumeric code — a 90% failure rate.
Despite the raw failure rate, the results were published in a February 2024 report with a headline touting microstamping as “technologically viable.”
The gap between failure and conclusion has become a recurring theme in the microstamping debate. The firearms industry has pushed back against this narrative for over a decade.
In the 2013-2014 case Pena v. Lindley, the Second Amendment Foundation fought California’s microstamping regulations. The CEOs of Ruger and Smith & Wesson both submitted declarations opposing it.
“Smith & Wesson does not believe it is possible currently to comply with California’s microstamping regulations. Quite simply, the state law requires the technology to perform at a level that it cannot,” Smith & Wesson President and CEO James Debney stated in court filings.
Ruger’s CEO Michael O. Fifer agreed: “There is no workable microstamping technology today, and Ruger believes that California’s microstamping regulations make compliance impossible.”
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Despite overwhelming data and pushback, states like California and New Jersey have continued to advance microstamping requirements as a way to combat gun violence.
In July 2025, California Attorney General Bonta released his own department’s report, reaching the opposite conclusion as NIST’s body of research.
“My office’s investigation into the technological viability of microstamping components has found that this technology is viable,” Bonta said in a statement . “Microstamping technology could help law enforcement match cartridges found at crime scenes directly to the firearms they came from. Today, my office released a report outlining the findings of our investigation in an effort to provide appropriate transparency as to the basis of our determination.”
Though Bonta reviewed much of the same data as NIST, that discrepancy in interpretation is what NIST’s letter places before Congress.
"There is significant disagreement regarding the viability of this technology,” the letter reads.
With state lawmakers continuing to advance microstamping legislation despite the evidence, the issue appears set to head for a fight in Washington.
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Additional Resources
- National Institute of Standards and Technology letter
- SAF Thanks Gun Companies for Support in CA Microstamping Case
- Attorney General Bonta Releases Report, Finds Firearm Microstamping Technology Viable: Press Release
- Commerce Dept. Informs Congress No Evidence Microstamping Is Reliable: NSSF