Does anyone know what this is? It is 2.225 inches in diameter and 6.75 inches long
Canadian 6 Pds 7cwt (57mm) dated 5/ 1943.
Example shown below (photo from BOCN).
Hopefully others will chime in a provide more information.
Thank you Brian, I have now been able to find more information now that you have pointed me in the correct direction.
The example shown in the first post could have been a reject from the production line. There is also the possibility it was taken as a souvenir by a factory worker.
It should have a copper driving band as shown in the photo of the complete round.
These bands were sometimes removed for the scrap metal value, but your projectile looks like the band was possibly never fitted.