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No.231 III/IVA CC/42


Well-Known Member

Picked this fuze up awhile ago. Was wondering if someone could help with internal parts diagram. Would also like to know what it was used for. Went through the provided list but wasnt much info.

Interesting note, the nomenclature III was overstamped with IVA .What modifications were made between III and IVA?


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I can't help you with what it was used with but, somewhere I believe I have a diagram for it.

The markings are interesting;

The 'A' suffixing the Mark number denotes a fuze similar to the previous converted Mark, but of new manufacture.

This would suggest the Mark VI was in fact a conversion of a Mark III and the amendations were of such a number or nature to warrant a new mark number. Normally a fuze subject to minor conversions would be denoted by having an asterisk stamped after the Mark number.

Thus your fuze is possibly a fresh manufactured Mark III incorporating all the updates from scratch, but caled a Mark IVA.

If it was new manufacture, it does beg the question why has the III been overstamped? The only thing I can think of is that maybe the nose cones had been manufactured and stamped prior to the contract being altered.

CC is the maker's mark, if I was sure it was a British manufactured fuze I would opt for Carron & Co of Falkirk Scotland who although were primarily ferrrous founders also had a Brass and Aluminium capacity. Digressing slightly, many British Pillar (post) boxes were cast by Carron.

My doubt as to the nationality of manufacture is the slash after the CC. This, if followed by a C, would denote Canadian manufacture.

Another possibility is the Chrysler Corporation.

Are there any other markings?


As a matter of fact,yes,there are two other marks that I didnt picture. There is a flame bomb ordnance mark and,confusingly, a broad arrow mark.

Also,next to the faming bomb stamp seems to be some very very light numbers,possibley lot number info. NF52157-69?6 42 Cant be for sure that those are 100% correct.


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I would suggest then this is of American manufacture, namely Chrysler. The pheon (broad arrow) denotes that it has been accepted for service (British). This might be lend/lease ammunition and the flaming grenade might signify that it is the property of the US Government. I have to confess I'm not completely au fait with American markings.


Ignore what I've written above about a Mark IV being a conversion of a Mark III, its all wrong. The Mark III differed from the I & II by having a weaker detent spring. The Mark IV differs in being fitted with a flanged detonator and also (the drawing is hard to read) to have a modified delay plug, detent plug, shutter detents and shutter. Thus, the IVA would have been of new construction, incorporating all the modified items made from new.

Still can't help you with what it was used with.




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Man thanks,its just nice to figure some of that out.
Maybe someone else has an idea what its used on?

Man thanks,its just nice to figure some of that out.
Maybe someone else has an idea what its used on?

HE Ammunition on following Equipments:
QF 25-Pr Gun
QF 3.7-inch How
BL 5.5-inch Gun/How
BL 6-inch How
BL 7.2-inch How

Banned at some time for training and practice. Mark IV not to be used with 25-pr Charge 3 or supercharge.

[Reference: Ammunition Maintenance Instructions for Army Ordnance Services]