Excavations near Shute unearthed the device on Wednesday afternoon.
Royal Navy engineers were called to the scene and the shell, believed to be from World War II, was detonated on Strete Gate Beach.
The police wanted to reassure the public any explosion heard in the area on Wednesday night was nothing to be concerned about.
Gas off in 4,600 South Hams' homes as temperatures plummet
Former factory could become a church
Accommodation for rough sleepers as temperatures plummet
Devon aid convoy team urges bay to twin with Ukrainian city
Mixed feelings for proposed Exeter student flats block
Future of Torquay police facilities set to be discussed
