Help Requested on 20mm Round

[NickyD]

Hi..

Sorry to bother you guys but I was wondering if you could help, my partners grandfather was a metallurgist during WW2 working on weapons design, however sadly he passed away recently and on going through the boxes we have a 20mm round, and really we are not sure what to do with it, obviously this was one of the designs he worked on, hence keeping it as a souvenir. But we have no idea how to identify it, or identify if it is inert or not (which is a worry) the stamp on the bottom reads K 1940 20mm UI and is next to a (ish) 5-7mm wide circular cavity that is 5-7mm deep, otherwise there are no other markings on the brass casing or black tip.

While I have been searching all over the intent for weeks, I have yet to find out what UI means or whether it is a type of propellant or not. At the moment I have no idea what to do with it, it would be nice to have it on display given the family link, however due to this uncertainty it sitting boxed in padding in a cool spot under the house, so any help would be appreciated..

Nick

 

[spotter]

do you have a photo going by your description of the headstamp its an inspectors dummy round,,a photo would help to confirm the id

 

[NickyD]

Thanks, I'll dig it out and get some pictures... (oh and I got the casing wrong, it's metal not brass *facepalm*).. I am hoping this is a dummy as it has got my partner interested in this topic given that it was her grandfather who worked on some of these designs (on the metallurgy side) however she was concerned it might not be inert, hence the worry and my checking..


BTW, may I ask, what is an inspectors dummy round, I realise I am showing my ignorance, however I guess we all have to start somewhere, thank you for your time responding.

 

[ydnum303]

Hi Nick,

Sounds like a 20mm Hispano round. Should be totally inert, as the "UI" indicates that it is an Inspector's dummy, Mk.1. The hole is where the primer would have been had it been a live round. The "K" indicates it was made by Kynoch, who were a branch of ICI, having been taken over by them after WW1.

Most Inspector's dummies are chrome or nickle plated; it could have been polished so much that the plating has been removed, but there may still be traces in the primer pocket, or the extractor groove.

Hope this helps.
Regards,
Roger,

 

[spotter]

Put it on display thats one very nice and safe 20mm hispano dummy round

 

[smle2009]

Yes very nice and not an easy one to find nowadays in that condition...Inspectors dummies were issued to unit armourers for the testing and adjustment of the 20mm cannon,normal drill rounds/dummies used by crews to practice loading ect were prefixed D on the headstamp

All the best
Tony

 

[ydnum303]

Hi Nick,

Your post has just beaten my reply! Inspector's dummies were rounds that were made up to the same weight as the "Service" round, and were issued to the inspectors in armament factories and to armourers in military units so that they could check the working of the mechanisms of any guns being made or repaired. They were plated to make them readily distinguishable from live rounds. They should not be confused with "Drill" rounds, (which usually had a "D" in the headstamp), which were issued to troops to practice loading and operating their weapons. Although some drill rounds were also chrome or nickle plated, or even made from cupro-nickle, they were made to lower tolerances than Inspector's rounds, and tend to be far more common. They frequently had holes and/or grooves in the case to make them easily recognisable.

Regards,
Roger.

 

[NickyD]

Thank you all for the wealth of information, that's a great relief and brilliant to know

We still have many documents and boxes to go through If I find out more details on the role he played I'll certainly let everyone know.

Thank you again for your help, this is certainly an interesting site, I have been reading and learning so much

 

[ydnum303]

Hi Nick,

Glad we could help!

Just a further note to say that if your partner's grandfather was involved in weapons design in WW2, any documents he left may well be of great interest to historians, so please do not throw anything out until you are sure that whatever it is, it is of no historical interest! Far too much knowledge and information has been lost over the years because Companies, organisations, and individuals have destroyed or thrown away documents and artefacts to make space, or raise money from scrap.

There will be many members on this site who could advise as to the interest or historical value of items if so required, and suggest appropriate conservation methods.

Regards,

Roger.

 

[smle2009]

just to muddy the issue,which is often the case for British Hispano rounds, photos of MkI DRILL round Mk3 DRILL/INSPECTORS round and a Factory dummy from Kynoch for in house use...as can be seen the Mk3 is marked up as a drill and inspectors round!,none of which are marked U or D!...don't you just love this hobby!

All the best
Tony

 

[NickyD]

Hi Roger..

We're still looking through and hypothesising why he had this as his specialism was weapons design, perhaps to test what they where designing??. I am sure we'll find out in time, and of course it would be nice to share that type of information with those interested.

Regards

Nick

 

[NickyD]

just to muddy the issue,which is often the case for British Hispano rounds, photos of MkI DRILL round Mk3 DRILL/INSPECTORS round and a Factory dummy from Kynoch for in house use...as can be seen the Mk3 is marked up as a drill and inspectors round!,none of which are marked U or D!...don't you just love this hobby!

All the best
Tony

View attachment 68594View attachment 68595View attachment 68596

Wow, thanks Tony, may I ask what that means? does the one we have still look like an inert inspectors round? as it feels like a real round, which was the aspect that worried my partner.

As I started off saying my partners grandfather was in weapons design (the metallurgy side) perhaps he worked on designing these types of rounds? I'm guessing here, but getting the dynamics/weight right could be the job for a metallurgist..

Regards

Nick

 

[smle2009]

Hi Nick,
yes, sorry most definitely a inspectors dummy and a very nice example too, completely inert and safe...just trying to show how varied these drill/dummy(and their markings) can be.

All the best
Tony

 

[NickyD]

Thank you for clearing that up Tony, it is really appreciated..

In the last few weeks I've certainly learnt a lot about the variety of ordnance emanating from our arms factories, and it has certainly been an interesting experience..

One that I think, might have me hooked

Regards

Nick