WW2 1942 British Dated 20mm Oerikon Ammunition Shell Casing

This particular 20mm casing was manufactured in RG – Radway Green, dated 1942

The “OeZ” marking means “Oerlikon, Loaded with Nitrocellulose powder”. This maring was used to differentiate the semi-rimmed Oerlikon rounds with the similar looking (but not interchangeable) 20m Hispano.

In British service, a “Z” stamped on the base of a case 20mm or below in calibre indicates that the case is loaded with nitrocellulose flake powder. This is opposed to the typical British Cordite “spaghetti” rod type propellant.