Lucy Stackler told a judge she put 11 bullets in a carryon bag when they fell from her closet in May and forgot about them. She said they belonged to her husband, who has a firing range in their basement.
"If I had remembered I had put them in there, I never would have brought them here," she said. "I'm not that crazy."
Judge Archibald Warner cleared her of the charges after a three-day trial.
Airport officials discovered the bullets before Stackler boarded a JetBlue flight to New York last month. No one apparently detected them when she flew from the U.S. to the British Caribbean territory.
Stackler, who lives in Oyster Bay, planned to fly back to New York on Saturday.
Last month, a 61-year-old tourist from Florida was sentenced to nearly two weeks in jail after a judge dismissed as "nonsense" her explanation that she forgot she was carrying a 9 mm magazine clip.
Attorneys said Lori DuBell discovered the clip during a JetBlue flight from Boston on Sept. 10 and then emptied the ammunition into a bathroom trash can, but did not tell the airline because she did not want to divert the flight.
The maximum sentence for importing a firearm or its components into Bermuda is five years and possibly a $10,000 fine.
Bermuda has allowed only licensed members of gun clubs to own weapons following the killings of the island's police commissioner, the governor and an aide in the early 1970s.