Brought in as part of the station's two-week weapons amnesty program, during which residents could turn in weapons without being prosecuted, the unidentified man told officials he simply no longer wanted the shell because it was getting too rusty, the International Business Times UK reported.
After bomb disposal experts from the Royal Navy arrived on the scene, officials ultimately concluded the weapon was not active and could be detonated in a safe environment.
"The projectile was probably from the 1950s and it is being destroyed in a controlled explosion," a spokesperson for the Devon and Cornwall Police Department said in a statement.
The gun amnesty stint saw residents turn in hundreds of firearms along with more than 20,000 rounds of ammunition, the outlet reported. Some of the weapons included air rifles, a Tommy submachine gun and even a WWII-era Webley revolver.
This is by no means the first time such an incident has occurred in the UK.
In June, a man walked into a police station in Surrey with a WWII bazooka he dug up while gardening and in a separate incident two men magnet fishing discovered a Panzerfaust, a type of anti-tank bazooka.