WASHINGTON (NYTIMES) - The United States is in the middle of a great gun-buying boom that shows no sign of letting up as the annual number of firearms manufactured has nearly tripled since 2000 and spiked sharply in the past three years, according to the first comprehensive federal tally of gun commerce in two decades.

The report, released by the Bureau of Alcohol, Tobacco, Firearms and Explosives on Tuesday (May 17) - three days after a mass shooting in Buffalo, New York, left 10 dead - painted a vivid statistical portrait of a nation arming itself to the teeth.

Buyers capitalised on the loosening of gun restrictions by the Supreme Court, Congress and Republican-controlled state legislatures.

The data documented a drastic shift in consumer demand among gun owners that has had profound commercial, cultural and political implications: Starting in 2009, Glock-type semi-automatic handguns, purchased for personal protection, began to outsell rifles, which have been typically used in hunting.

Embedded in the 306-page document was another statistic that law enforcement officials find especially troubling.

Police recovered 19,344 privately manufactured firearms, untraceable homemade weapons known as "ghost guns," in 2021, a tenfold increase since 2016.

Law enforcement officials say that has contributed to the surge in gun-related killings, especially in California, where ghost guns make up as many as half of weapons recovered at crime scenes.

The numbers released Tuesday revealed an industry on the rise, with annual domestic gun production increasing from 3.9 million in 2000 to 11.3 million in 2020.

A relatively small percentage of guns produced domestically are exported overseas, so those numbers are an accurate reflection of gun-buying habits, according to ATF officials.

Currently, there are around 400 million guns in the United States, according to a 2018 survey conducted by the nonpartisan Small Arms Survey, which monitors gun ownership.

The statistics, culled by ATF's research division from industry, academic and government experts, offered few major surprises. Many of the broader contours and conclusions have been widely known through other sources or anecdotally for months, even years.

But the report's release nonetheless represents a significant victory for advocates of gun control.

While Democrats have failed at their larger agenda of limiting easy access to firearms, especially semi-automatic rifles, they are succeeding in gradually pulling back an informational blackout curtain that has obscured gun commerce data since Mr George W. Bush's administration.

A year ago, President Joe Biden ordered the ATF, an undersized agency with the oversized task of enforcing the nation's gun laws and regulations, to collect and analyse 20 years of gun data after a series of mass shootings around the country.

In the introduction to the report, Mr Gary Restaino, the bureau's interim director, wrote that the purpose of releasing the data was to "prevent diversion of these firearms from the legal to the illegal market."

During a White House summit about reducing violence Tuesday, the deputy attorney-general, Ms Lisa Monaco, underlined a similar point, saying, "We can only address the current rise in violence if we have the best available information and use the most effective tools and research to fuel our efforts."

The report, while eagerly anticipated, is considered less consequential than a coming analysis of weapons used to commit crimes - which will tap law enforcement, academic and public health sources - to offer an equally comprehensive picture of trafficking patterns.

"It's important to know what the scope and size of the overall market is, and the commerce report sheds light on that," said Mr Nick Suplina, senior vice-president with Everytown for Gun Safety, the gun control group founded by former New York Mayor Michael Bloomberg.

"But the next logical step is to get the data on crime gun recoveries, to get that information back in the public sphere, so we can find out how these guns are going from legal manufacturing to illegal use," Mr Suplina added.

That report is expected to highlight the role of illegal straw purchasers - legal buyers who sell weapons to people barred from purchasing handguns - and perhaps identify federally licensed dealers who are responsible for selling the greatest number of weapons later used in crimes.

The gun industry has long resisted the disclosure of some firearms data collected by ATF. A series of Republican-sponsored measures, pushed by the National Rifle Association, restricts officials at the bureau from releasing trace data and other information to the public.

The boom in gun production appears to have been partly driven by the expiration of the assault weapons ban in 2004.

After the law was allowed to lapse, "manufacture of the types of semi-automatic rifles and pistols previously designated to be assault weapons steadily increased, particularly AR-type rifles and pistols, which are now commonly referred to as 'modern sporting rifles' and 'modern sporting pistols,'" the report's authors found.

The data compiled by ATF covers a 20-year period, but the graphs included with the report show three periods of intense consumer volatility.

One was in 2013, after the reelection of President Barack Obama and the mass shooting in Newtown, Connecticut, which prompted calls for increased gun regulations. The second was in 2016, during the presidential campaign.

The third unsettled period began in 2019 and extended through the 2020 election and pandemic.

Gun production increased across the board during that time. But demand for semi-automatic handguns rose at the fastest rate on record, with pistol production rocketing from around 3 million to 5.5 million annually, the report found.

The number of imported guns, of all types, has also been rising sharply, doubling from around 2 million per year a decade ago, to more than 4 million in 2020, a record.