Cerberus Capital Management spent nearly a decade searching for someone—anyone—to buy Remington Outdoor before the maligned gunmaker filed for bankruptcy earlier this year. Now, the company's management has reportedly turned down a cash offer that could have been worth more than $500 million.

The Navajo Nation submitted a surprising bid to acquire Remington for between $475 million and $525 million, according to The New York Times, part of a proposal to reshape the gunmaker in a friendlier image. The Navajo proposal reportedly called for Remington to embrace police and defense contracts rather than selling its weapons to civilians, to invest in developing safer "smart guns" and to employ Navajo members to assemble Remington products.

The Native American tribe, which has more than 350,000 members, also planned to stop selling controversial AR-15 rifles to consumers, again per the NYT. Cerberus and Remington became the subject of considerable controversy in 2012 after a shooter used one of the company's AR-15s to kill 20 children and six adults at Sandy Hook Elementary School in Connecticut.

It's believed the Navajo Nation planned to pay for the bid with cash from its multibillion-dollar investment trust. But Remington chose to reject an offer that surely would have resulted in a considerable executive shake-up. The company reportedly said it was "not prepared to engage with third parties."

Cerberus handed over control of Remington earlier this year to creditors including Franklin Templeton Investments and JPMorgan Chase as part of Chapter 11 bankruptcy proceedings. The firm acquired its stake in the arms dealer in 2007 as part of a deal that merged Remington into a larger gun-industry entity called Freedom Group.

Related read: Gunmaker Remington becomes latest PE-backed bankruptcy victim