Unknown 57 mm case

[Hoeksel]

I am in contact with a non-collector who has some cases for me. He also has a (if measured correctly) 57x470R92 mm case. Case looks like a enlarged 6 pounder case. Does anybody recognize these measurements? The case is most likely Swedish navy, since there are no headstamps I can't say what period.

The case does not have a groove on the bottom like the typical 40 mm and 57 mm Bofors cases. It has a closed primer hole, which could indicate a half product. Last interesting feature is that near the primer hole the case looks concave. Also this may indicate a half product. I can only show a picture of the bottom.

 

[Hoeksel]

Now that I have this case in my posession I can say a bit more. I have the feeling of it being an unfinished case, based on the 57 mm post-war Bofors navy gun.

Measurements: 57x471R92.3 and weight 1.766 kg (including brass cover plate in the primer hole)
The bottom is flat and contains a brass cover plate for the primer hole (looks as made for a primer hole I must admit opposed to home made creativity).
No clear markings, I will try later to remove the brass cover plate and clean up to see if I can find any markings.

Since I do not have a 57 mm Bofors as comparison, can somebody show me how the foot looks of such a case and what the weight is? I have no clue what this is.

 

[Falcon]

It looks to be an unfinished case that was removed from the production line before the head was machined.