German naval canon/sight part 3,7cm.?!

[dutchflecktarn]

Hi Folks,

Found this piece of hardware, is German navy that is easy to see, but have no clue if it's a part of a gun sight or.........
Seen on pic's that it can be set for Übungsladungen and 'also' for 3,7cm Abkommkanone.
I have the 3,7cm abkommkanone for the 10,5cm c/30 naval canon, can it be that it is some sort of gunsight-adjusting- tool?!
Hope some will have more info regarding this piece.

Best Regards

[dutchflecktarn]

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[dutchflecktarn]

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[dutchflecktarn]

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Nobody?!

[mlespaul]

This looks like a device that measures/verifies the correct diameter for the subcaliber round inserts for the firing of practice ammunition.