Three fake SA80 rifles were taken during a break-in to the hall in Newport-on-Tay, Fife, along with cash.
The imitation guns are used for training and do not function as firearms.
The break-in to the property on Victoria Street happened between noon on Wednesday May 2 and 11am the following Wednesday.
Detective Inspector Chris Mill said: “We are treating this incident with the utmost priority and have a dedicated team working to establish the whereabouts of the equipment.
“We are keen to hear from anyone who may have seen, or been offered, any of the equipment, or can help us trace their whereabouts.”
An Army spokesman said the service is aware of the theft.
Police can be contacted on 101 or information given anonymously via Crimestoppers on 0800 111 555.