Looks like an 18-pdr shrapnel round from the Great War.
Fuse is the Number 80, Time and Percussion; it could be set to go off on impact OR after a given time.
MILLIONS were made during th 1914 - 1918 period, millions MORE during the Second War, although mostly HE.
Many of them were marked KpZ: Krupp-patent Zunder: Krupp's patent Fuse. HUGE lawsuit after the war based on royalties: we cheated them. That's okay, they cheated us massively on Maxim Gun royalties. Only person who lost was Sir Hiram Maxim; he did all the work. Figures: Government NEVER loses.
If it were a dud which had been fired, there would be grooving from the rifling on the rotating band. There is none, so this one has never been through a gun. Most likely a war souvenir that some Gunner dewatted to take home when it was all over.
SUPER interesting.
Text Book of Ammunition - 1924 has diagrams and specs on the Number 80 fuse. You can download the entire book over at Milsurps dot com.