In the first month of expanded background checks for gun purchases, 561 people who sold guns in private transactions complied with the new law. Ten denials were issued.

And although the numbers represent only the first month’s worth of data, the total figure of private checks is far below the percentage of sales that Democrats had claimed were going unchecked.

The hotly debated measure in the past legislative session resulted in threats of violence against lawmakers and protests outside the state Capitol.

Now, with the initial results out — after months of back-and-forth battles — some of the lawmakers who fought the hardest on both sides of the measure seized the numbers to say they support their claims.

The sponsors of House Bill 1229 said the 561 background checks processed in July by the Colorado Bureau of Investigation for private sales and the denials issued means one thing: The bill is working.

“I’m excited to hear that 10 people were denied access to guns because they were unqualified,” said state Rep. Rhonda Fields, D-Aurora, one of the two sponsors of the bill.

Politicians who battled against the legislation, calling it an infringement on Second Amendment rights, said the number of denials is inconsequential and not worth the burden put on Colorado residents.

“It is a good indicator of how micromanaging everyone’s life has such small returns,” said state Sen. Kevin Lundberg, R-Berthoud. “Those 10 denials, if they are even accurate, are not persuasive at all.”

During the past legislative session, Lundberg called the universal background-check bill “one of the worst bills we’ve seen this year.” These new figures, he said, reinforce that statement.

“In no way am I swayed,” he said.

The CBI does not list the specific reason for each denial issued for private or licensed-dealer sales, but denials can be triggered by a felony, domestic-abuse charge or active warrant, among other factors. There are some false positives, which can be appealed and overturned.

State Sen. Morgan Carroll, D-Aurora, the other sponsor of the bill, said the 10 denials have significant impact.

“A gun in the hands of the wrong person is devastating,” Carroll said. “If it (the law) keeps a gun out of the hands of one person who shouldn’t have one, then it is working.”

Not every lawmaker was aware of the private-sale background-check numbers, including the sponsors.

Gov. John Hickenlooper, who faced heavy criticism for signing the new gun-control legislation into law, could not be reached for comment because he is recovering from hip surgery. However, Eric Brown, the governor’s spokesman, said, “The new law is intended to keep guns away from people who shouldn’t have them, and it appears to be working.”

Fifty-five sheriffs in the state are part of a lawsuit filed to have the measure declared unconstitutional.

“As we have explained in our court filings, a universal background check law has to be functional and usable in a practical sense, and this one is not,” said Dave Kopel, a University of Denver law professor and staff member of the Independence Institute think tank.

Kopel is representing the sheriffs in their legal challenge.

State Sen. Greg Brophy, R-Wray, said the law has not made anyone safer.

“It was already illegal to sell or transfer a gun to someone you knew couldn’t legally have one,” he said.

In addition, Brophy said, during the legislative debates for the bill, Democrats claimed nearly 40 percent of gun sales were done privately, a figure far below what the CBI data show. The 561 private checks processed in July represent 2.9 percent of the total number of background checks for gun sales that month.

“So, either the Democrats were wrong in that statement or a tremendous amount of people are not following the law,” Brophy said. “I think it’s the latter.”

Ryan Parker: 303-954-2409, rparker@denverpost.com or twitter.com/ryanparkerdp