Surprise from the beach

[ille27]

3 years ago, my cousin found this stone with sea shells at the beach on an Danish island!
3 years later he rediscovered it in his garge in a box with other shells and stones, but meanwhile time rust and physical force of nature did changes...
the stone break into pieces!
Then a phonecall came to me: "wuaahhh you must come here, hurry up!"
The stone fell down and the whole misery discovered, and lucky break, the bottom plug of the inside item rolled around.
See the pictures to give impressions of inconspicuous items that could be found at beaches...
He thought that time it is an fossilisation!

Experts: is this an english 2cm grenade?

Thank you for response!

ille

 

[Falcon]

I believe that is a British 20mm Hispano practise projectile. These projectiles were hollow, with a steel plug inserted into the base.

 

[ille27]

Thank you for response, Falcon,
Inside was nothing except frowsty air!
May be they did not insert the plugs all the time?

 

[HAZORD]

@ille27, what is the diameter of the projectile now? Comparing the body to the rotating band, it looks like a good amount of the outer surface has rusted away.

 

[smle2009]

more than likely a Hispano tracer which had a much thinner 'base plug' for obvious reasons.....another interesting point Hispano ball and tracer were not called practice but were ball or tracer,20mm Oerlikon ball and tracer were called practice

 

[AMMOTECHXT]

I once found about 40 such lumps in one day on one beach, exposed by coastal erosion - never found any there before or since. The steel of the projectile had corroded completely, leaving just the driving band in black muck.

 

[ille27]

@ille27, what is the diameter of the projectile now? Comparing the body to the rotating band, it looks like a good amount of the outer surface has rusted away.

Hello Hazord, diameter is only 18mm left!