World War Two percussion primer question

[uksweetheart]

Hi, I'm new to the group so please bear with me if I make any mistakes
I found this forum by accident as I was looking to ID and object that my husband had found while out metal detecting near to where we live.
I found the original message about the primer so that is how I found out what it was and AMMOTECHXT gave some fantastic info about it but my question today is how would I check to see if this is still live or safe?
I've added some pics so you get an idea of what condition it was in when found.

 

[Slick]

Being hollow and the primer struck, it is "spent". You'll be getting numerous responses here about leaving things alone like that and notifying authorities.
Nice find, tho.

 

[TimG]

Going by the length of the item - Primer, Percussion, Q.F. Cartridges, No.9 Mk. III. Associated equipments - Q.F., 3.7-in. Mks. 1-3 Guns (Anti-Aircraft) There were others but they had not been invented in 1941.

TimG

 

[uksweetheart]

Thank you for your replies, I don't suppose anyone has a diagram of an Anti-aircraft gun showing the position of the primer. I wish I knew it's history

 

[tankbarrell]

It's not part of the gun but is the percussion primer that screws into the base of the cartridge case. The firing pin in the gun hits the centre, hence the indent and ignites the primer charge which flashes through the holes in the flash tube and ignites the main propelling charge. All in milliseconds!

 

[uksweetheart]

Thank you