APDS 17 Pounder

[jvollenberg]

Any ideas on who and what this is? I know it is a 17 pounder APDS. I am trying to get the country and nomenclature.

Also, and data on the item would be nice too ...

And if nothing else, these are some nice images to share.

DIA: 80MM (full round)
DIA: 59MM (Sabot)
Length: 203MM (Sabot With tracer)
Length: 201MM (full up item)

Joe

 

[Weasel]

Hi Joe,
Have a look at this thread for some info, this one has 17pr 77mm marked on it as well. http://www.bocn.co.uk/vbforum/threads/54261-17-pr-APDS-Question?highlight=17pr+77mm Best regards Weasel

 

[SG500]

Any ideas on who and what this is? I know it is a 17 pounder APDS. I am trying to get the country and nomenclature.

Also, and data on the item would be nice too ...

And if nothing else, these are some nice images to share.

DIA: 80MM (full round)
DIA: 59MM (Sabot)
Length: 203MM (Sabot With tracer)
Length: 201MM (full up item)

Joe

Nice items Joe.
The core on its own looks more like a 20 pounder than a 17 pounder, the profile looks wrong for a 17 pounder unless its the angle of the photograph.
Dave.

 

[jvollenberg]

I think it is the angle. When we took the pictures we made sure they went together.

So by the other thread, this is a MK 1?

Joe

 

[TimG]

The projectile was made by JMB - James Mackie and Son, Belfast.

TimG

 

[MINENAZ16]

Diagram of 17pr APDS MK1 for example

 

[AE501]

Hopping between the thread and the link things fall into place.

6pr 7cwt APDS was introduced in March 1944, followed in August 1944 by 17pr APDS.

77mm for the Comet did not appear until near the end of 1944, at which time it was decided that 77mm should be added to the projectile description, because the same shot was used for both (this was the case with some of the other types of projectile and it says it in the pamphlet).

Hazord made the point that the red ring was missing, but that is an in-service requirement and as this is an experimental APDS not intended for in service-use there is no need for it. In any case there may not have been a tracer fitted for the experiment.

 

[Przezdzieblo]

Tappered projectile body was typical for Canadian pot sabots.


P.S.
Check this topic.

 

[jvollenberg]

Here is a Canadian Version ... although I am not sure what makes it Canadian.

Joe

 

[TimG]

APDS/T.QF.17PR 77MM.CDN.MK1 - CDN: Canadian

TimG

 

[jvollenberg]

Can someone tell me what factory CDN is?

Joe

 

[Spaceinvader]

Can someone tell me what factory CDN is?

Joe

CDN is Canadian, Canada produced its own model of the APDS independent of the UK’s model. The manufacturer will likely be stamped elsewhere on the projectile (both the sabot and sub-projectile in my case).

The same example I have was made by C.C.M. (Canada Cycle and Motor Limited) who still exist today producing hockey and sports equipment.

 

[RichardB]

This projectile is something that I’ve always been meaning to do some more research on, but haven’t really got round to it.
- Do you have a photo of this projectile in a 17pr case?.
- Do you know why some are marked are APDS and some are APPS?
- Do you happen to know why Canada went with a slightly different design?
- Do you happen to know when they were first used combat/ issued to units?

Apologies for the plethora of questions.

 

[Spaceinvader]

This projectile is something that I’ve always been meaning to do some more research on, but haven’t really got round to it.
- Do you have a photo of this projectile in a 17pr case?.
- Do you know why some are marked are APDS and some are APPS?
- Do you happen to know why Canada went with a slightly different design?
- Do you happen to know when they were first used combat/ issued to units?

Apologies for the plethora of questions.

I can’t answer all these however I do have some for the research I’ve done for mine in the past.

I believe it was DJ who made a cutaway of a complete cartridge which showed the proper method of threading & gluing the projectile skirt over the special “coned” case mouth. It was likely posted here on the BOCN but I will have to find the post.

If I’m correct as well it’s likely the Canadian model never saw combat, it was produced late in the war to fix the problems of the British design being inaccurate at longer ranges. What is also interesting is the US 76mm M331 APDS meant for the M41 Walker Bulldog medium tank is essentially a direct copy of the Canadian 17pdr design although the connection I am unsure of.

 

[RichardB]

I believe it was DJ who made a cutaway of a complete cartridge which showed the proper method of threading & gluing the projectile skirt over the special “coned” case mouth. It was likely posted here on the BOCN but I will have to find the post.

This was the reason for my first question...
Is it a standard 17pr case or a modified case. if modified, does it still fit in the breach of the 17pr, or is it actually a different gun..... Which makes sense given the diagram you've provided, as it shows 76G & M331 (Walker Bulldog), but doesn't explain why both of ours are marked 17pr / 77mm. Having owned Walker Bulldog rounds in the past, it certainly resembles the cannelure design of them, rather than the 17pr. Therefore the picture on the wikipedia page for the 17pr is incorrect.

Your projectile is marked APDS, mine is APPS, yet both have essentially the same design with a core, three petals and a base "pot". perhaps just a change in terminology given the pond between us?.

 

[RichardB]

It was produced late in the war to fix the problems of the British design being inaccurate at longer ranges.

Regarding this, I have a document showing the fix for the 17pr APDS inaccuracy was to enlarge the exit bore diameter of the muzzle brake on the 17pr barrel dated 18th August 1944, with discussion on fixing in the field. It certainly explains why the Comet didnt suffer these issue, given the projectiles were identical.

Ill dig it out and add it here.

 

[Spaceinvader]

This was the reason for my first question...
Is it a standard 17pr case or a modified case. if modified, does it still fit in the breach of the 17pr, or is it actually a different gun..... Which makes sense given the diagram you've provided, as it shows 76G & M331 (Walker Bulldog), but doesn't explain why both of ours are marked 17pr / 77mm. Having owned Walker Bulldog rounds in the past, it certainly resembles the cannelure design of them, rather than the 17pr. Therefore the picture on the wikipedia page for the 17pr is incorrect.

Your projectile is marked APDS, mine is APPS, yet both have essentially the same design with a core, three petals and a base "pot". perhaps just a change in terminology given the pond between us?.

As I understand it the case was modified to fit the rounds specifically (hence the coned case) however the case itself was still a standard 17pdr case and still fit the standard 17pdr guns. I have read that the glue used to secure the projectiles was too strong initially and a replacement was needed for the glue.

Also while I have zero info to back this up my initial thought was the “17pdr / 77mm” markings might be due to Canada being right above the US who mainly uses millimeters to designation ammunition rather than pounds as the British / Commonwealth did. To avoid confusion both are stamped on?

 

[charley777]

As I understand it the case was modified to fit the rounds specifically (hence the coned case) however the case itself was still a standard 17pdr case and still fit the standard 17pdr guns. I have read that the glue used to secure the projectiles was too strong initially and a replacement was needed for the glue.

Also while I have zero info to back this up my initial thought was the “17pdr / 77mm” markings might be due to Canada being right above the US who mainly uses millimeters to designation ammunition rather than pounds as the British / Commonwealth did. To avoid confusion both are stamped o

 

[charley777]

Projectile suitable for use with two different case sizes. The original 17 Pr and the later 77mm (which was actually, like the 17Pr, a 76.2mm calibre. It used the 3inch 20cwt sized cartridge case).

 

[Gspragge]

Quote; " I believe it was DJ who made a cutaway of a complete cartridge which showed the proper method of threading & gluing the projectile skirt over the special “coned” case mouth. It was likely posted here on the BOCN but I will have to find the post."

I would like to see this also, it impies that the case goes into the projectile versus the projectile going into the casing -
So it would be improper to put one of these into any old 17pr or 77mm case as is ~