The crimped top of this British .303 rifle cartridge shows it is a 'blank', or training round, that never carried a bullet. The headstamp (the writing on the base) indicates this dates to the Second World War.
The primer (the central disc in the base) has not been dented by a firing pin, and the crimping has not been opened out by the explosion of hot gases, indicating the round was live and potentially dangerous when it was found in the garden of a private home, but it was promptly made safe under professional guidance.
Material: metal
Period: Modern
Find spot: Hampstead Road, Brislington, Bristol. ST 612710