By KEN RITTER | Associated Press

LAS VEGAS (AP) — A gun rights group wants Nevada's elections chief to throw out a proposed 2016 ballot measure that would tighten background checks for anyone buying firearms from private sellers or gun show exhibitors.

In a letter obtained Monday by The Associated Press, Nevadans for State Gun Rights tells Secretary of State Ross Miller that initiative proponents missed a deadline to deliver signatures to one clerk. The group also says some pages lack a proper signature-gatherer's affidavit, and some signatures are dated after the affidavit was notarized.

Petitions were turned in Nov. 13 to the Storey County clerk, said Don Turner, head of the gun rights group. That means proponents not only missed the Nov. 12 deadline there, they also missed a requirement to submit documents to each of Nevada's 17 county clerks on the same day, he said.

“Those are problems we found in just one county,” Turner said. He said some petition pages lacked a required affidavit, a circulator was from Washoe County, not Storey County, and 52 signatures were dated after the Oct. 25 notary date.

Turner said he expects to find more irregularities with petitions submitted to clerks in 10 other northern Nevada counties. The State Gun Rights letter is dated Nov. 25.

Nevadans for Background Checks spokesman Jack Warner said his group is confident the measure will be certified.

Warner said initiative proponents submitted nearly 247,000 signatures Nov. 12 to qualify for the measure requiring universal background checks for all sales and transfers of firearms.

The number of valid signatures needed statewide is about 102,000.

Miller's office hasn't validated signatures. Clerks in the state's 17 counties have until Thursday to sample petitions and report any irregularities, secretary of state's office spokeswoman Catherine Lu said.

Nevada requires criminal and mental health background checks for gun buyers making purchases from licensed dealers, but not for purchases from private sellers or exhibitors at gun shows. The screenings aim to prevent gun purchases by convicted felons, domestic abusers and people with severe mental illness.

The Nevada initiative, like a measure that passed in November in Washington state, has backing from Everytown for Gun Safety, a gun control group founded and funded by former New York Mayor Michael Bloomberg.

Its opponents include Turner, who also heads the Nevada Firearms Coalition, a political action committee affiliated with the powerful National Rifle Association. Turner said the NRA has no connection with Nevadans for State Gun Rights.