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.
Exeter concede 10 goals as Man City demolish Grecians
Match Report: Manchester City 10-1 Exeter City
Exeter City fans dream of glory in Manchester
Third round FA Cup game is biggest for years
Pleas for multi million pound road scheme to go further
Council has no plans to increase budget
Cathedral light show keeps audiences coming back
REVIEW: 'The Storytellers' by Luxmuralis
Debate over Exeter and Plymouth elections taking place
Opportunity to discuss whether elections should be postponed
