20mm Hispano Suiza Case marking's

[falcon5nz]

G'day all. Got a round and just need some help interpreting the markings.

SWN=Swynerton
77= Lot 77
53=1953 (Year of filling)
HEI=High Ex. Incendiary
CE=Explosive filler? If so what is CE?
4Z=? (4 second fuse delay maybe?)

Please correct me if I'm wrong.

And while I'm on it I still can't figure out the "N12Z" marking on my Oerlikon shell that I asked about here. Just hoping it will jog a memory

Nick

 

[Falcon]

The 4Z Means it is mark 4 of that loading with nitrocellulose propellant.

 

[falcon5nz]

Thanks mate. Any ideas on CE or N12Z?

 

[Tony Williams]

CE stands for Composition Exploding, aka Tetryl. IIRC this was mainly used by the USA.

 

[exat808]

The 1971 edition of The Service Textbook of Explosives JSP333 confirms that CE was first used as a pressed filling for 20 and 30 mm shells during WW2. An automatic hydraulic press was developed to make it feasible.