Breech loading chamber for ID

[fernando]

This one is already known to the forum; but this time the question is different; to find out its possible origin.
I ignore whether these chambers have patterns exclusive to each country and if it is possible to tell their origin by just looking at their shape.
It would be great if one (or more) of our members could define its country of origin.
Length 20 cms, caliber 45 m/m, exterior width 9 cms., weight 6,6 kgs.

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