Breech loading or Mortar ?

[Marcus den toom]

Not really sure what it is, could be a mortar ( it is missing the protruding powderpan though).
What does make me wondee is the seemingly moulded shape of the piece. It was not made like any other barrel of age i know (wrought and hammered). It was cast and also has non functional rings around it, mostly seen with asian arms.

Do you know the provenance?
Best,
Marcus