Like many other politicians before him, U.S. Sen. Bernie Sanders, I-Vt., repeated a false claim that 40 percent of guns are sold without a background checks.

"We have to end the absurdity of the gun show loophole," Sanders said Feb. 18 on NBC’s Meet the Press. "Forty percent of the guns in this country are sold without any background checks."

Three years after we first debunked this statistic, it’s still not true. The statistic comes from a 20-year-old study by the National Institute of Justice that looked at gun owners’ responses to a 1994 national survey asking how they got their weapons.

The study found that 30 percent to 40 percent of all gun transactions were made through an "off-the-books" transfer in which a background check wasn’t required.

The finding has been cited widely by gun control advocates. Former Virginia Gov. Terry McAuliffe earned a Mostly False when he used it, and a Florida gun control advocate earned a False in 2017 after the finding was diminished by new research.

The latest research suggests the percentage is almost half of what Sanders cited.

The sample size of the 1997 study was very small, with just 251 participants. Furthermore, the statistic stems from survey data that included firearms given as gifts or inheritances, not just sales. This is an important point.

When the authors of the NIJ study — Jens Ludwig of the University of Chicago and Philip Cook of Duke University — adjusted the results to include only the guns sold (not given), the number sold without background checks declined to between 14 percent and 22 percent.

That statistic more closely resembles the new findings in a relatively new 2017 study.

Researchers Matthew Miller, Lisa Hepburn, and Deborah Azrael published a study in the January 2017 edition of the journal Annals of Internal Medicine that was specifically undertaken to update the 1994 data.

The researchers asked 1,613 adult gun owners where and when they acquired their last firearm, including whether it was purchased, and whether they had either a background check or were asked to show a firearm license or permit.

The answer: 22 percent obtained their gun without a background check. That’s about half of the 40 percent figure that has gained wide currency for more than two decades.

In fact, Cook wrote an accompanying editorial in the journal, headlined, "At last, a good estimate of the magnitude of the private-sale loophole for firearms."

In it, he wrote, "Even though I bear some credit (or blame) for the earlier estimate, I could not be more pleased to be done with it, given that it is based on data from a survey done more than 20 years ago and that, in any event, never directly asked participants about background checks."

"It appears the number he cited may be outdated," Sanders spokesman Josh Miller-Lewis told PolitiFact Florida in an email. "But whether it’s 40 percent or 22 percent of guns being acquired without a background check, millions of Americans still obtain guns without background checks. That's absurd. No one should be allowed to purchase a gun without a vigorous background check."

Our ruling

Sanders said, "Forty percent of the guns in this country are sold without any background checks."

That statistic is outdated. It stems from a 20-year-old survey that has been overtaken by another study that shows that 22 percent of gun buyers obtained their weapons without background checks. That’s just over half the percentage in the zombie claim Sanders cited.

We rate this claim False.