Vice President Joe Biden once again used the 20-year-old statistic on background checks today that he and President Obama have repeatedly cited in their push for tighter gun control laws.

Obama has already been called out for saying 40 percent of all gun sales don’t require a background check under current law, a number incorrectly pulled from a decades-old report.

But Biden pulled out the statistic several times during a Google+ hangout on gun violence this afternoon to explain the importance of expanding background checks to private gun sales and gun shows. At least 80,000 of the people run through the background check system each year aren’t allowed to own a gun, he said. With as many as 5,200 gun shows in the U.S. each year, the 40 percent statistic means at least 30,000 people who buy a gun in a private transaction aren’t legally allowed to own that gun, Biden said. The difference is there’s no background check to stop the purchase.

“A significant portion of those sales require no background checks, none whatsoever,” Biden said.

Because background checks don’t apply to all gun sales, people can walk right by Dicks’ Sporting Goods and buy a gun in the field behind the store without any check on their criminal and mental health history, he said.

But earlier this month, The Washington Post gave the 40 percent claim a “three pinocchio” rating. The Post explained that while Obama and Biden say “40 percent of sales,” the study they’re citing uses the number to refer to transactions, which includes gifts and inheritances as well as purchases.

That detail changes the results: when gifts, inheritances and prizes are accounted for, the same study shows 26.4 percent of people did not receive their gun through a federally license firearms dealer.