A World War II German machine gun and a rifle have been stolen during a break-in at a lock up garage in Gorleston last week.
Thousands of rounds of blank ammunition were also taken, but police said the weapons had been deactivated.
The break-in was one of eight on lock-up garages in the coastal resort.
The owner of the weapons, who did not want to be named, uses them at military living history shows but doubts if they were specifically targeted.
He also said that the amount of ammunition stocked was normal for anyone involved in the activity.
He added: "With public shows you get through a lot of rounds and they are fairly cheap so we get them in bulk.
"Anyone involved in living history shows will carry similar amounts.
"I just think that whoever broke in was picking on garages at random - I don't think we were a specific target."
The break-in was discovered on 26 March but the lock up had not been visited in the 48 hours before.