The pair was jailed after bringing two air-gun silencers into the country as a gift for a hunting buddy.
Federal officials released Garry Latcham and George Hope after they pleaded guilty to a felony charge failing to declare the $55 silencers on U.S. customs forms.
The men traveled from England to North Carolina in November for a week of hunting with a friend in Person County.
They were arrested when they went to the Raleigh-Durham International Airport to pick up a lost bag, which contained the silencers.
Customs agents thought the men were terrorists, but federal prosecutors later admitted to a judge they were vacationers with no criminal intentions.