An ex-Marine in Minnesota is seething after a TSA supervisor confiscated a hollowed-out ammo cartridge from his necklace — and a cherished love letter hidden inside, according to a report.

Aaron Bradley, a 43-year-old vet with previous tours in Iraq and Afghanistan, was walking through a security checkpoint on Monday at Reagan National Airport in Washington when the manager said the engraved cartridge wouldn’t be flying with him, saying it resembled a “simulator of some kind,” the Star Tribune reports.

“I don’t even know what that means,” Bradley told the newspaper. “It was 100% approved by the TSA. There is nothing that would warrant what happened. There needs to be repercussions.”

Bradley, of Eagan, said the item wasn’t an issue for TSA screeners days earlier when he flew out of Minneapolis for a reunion with his military buddies. He pleaded with the female supervisor to allow him to keep the cartridge engraved with the Marines emblem, but the effort was fruitless, he said.

Bradley then watched as the supervisor coldly tossed away the one-of-a-kind pendant, which was given to him as a Christmas gift in December by his girlfriend. He was allowed, however, to keep two other items on his necklace, including a cross he wore during his tours of duty, he said.

“She said, ‘You can file a complaint,’ and she handed me a card,” Bradley recalled. “She didn’t care … The necklace was near and dear to my heart.”

Bradley’s girlfriend, Janelle Verke, said he’s now considering contacting an attorney.

“We know it’s gone forever,” Verke told the newspaper. “There needs to be accountability.”

The TSA, however, told The Post that it has made arrangements to return the pendant to Bradley, saying that it was placed in a “prohibited items bin” and not the trash.

“In general, real and replica ammunition is not permitted past checkpoints,” a TSA spokeswoman told The Post. “An item of this nature is up to the discretion of the TSA officer.”