A total of 70 firearms have been surrendered in Gloucestershire during the first two weeks of the national firearms amnesty.
Police say most of the weapons that have been handed in are old, with some dating back to the two World Wars.
These include an artillery shell which led to the evacuation of parts of Gloucester recently.
Police have also been given a 250,000 volt stun gun.
'Don't post them'
Chief Inspector Ian Jones says there is still another two weeks of the amnesty left.
"Please bring the guns in. People know if they have them in their possession.
"All we ask is that they are brought in safely.
"Don't post them to us - as one individual has done," he added.
The amnesty ends on 30 April.
Six police stations are accepting surrendered weapons: in Gloucester, Cheltenham, Stroud, Cirencester, Coleford and Stow-on-the-Wold.