Miliitary?

[Ringo]

out of the Thames

brass casing with lead inside and one piece of brass sticking out. Other side may have broken off but doesn't appear so:

 

[adammack]

Looks like a pinfire pistol round, unfired!!

 

[hicky1300]

Definitely a pinfire round & live. Sorry Ringo looks like another nice find to be lost!!
As I said on your last post - do not be too surprised by what Old Father Thames will give back!!

 

[Ringo]

Thanks all. The police station will be busy! )