Anthony Journeaux (74) admitted the three offences in the Magistrate’s Court in November.
At the time, the court heard that officers had visited his home on 15 July and found that he had an air rifle and air pistol but no licences for either.
They also found a blank-firing revolver, adapted to fire noxious gas.
Journeaux told the court he had contacted the police 10 weeks before their visit.
He said: “I’ve been asking them for months, asking them to come to my home.”
He added: “I did buy the weapons but I never took them out of the house.”
He was sentenced at the Magistrate’s Court this week. Assistant Magistrate Peter Harris said: “There was no suggestion that you used them or threatened to use them.”
He also ordered that the three firearms be destroyed.