[fernando]

The authenticity of this piece (as being Portuguese or not) doesn’t necessarily have be questioned by its small dimensions.
There were in fact small bronze ‘berços’ (cradles), cast in Lisbon, of the size fit to equip in batels (ships ‘multiuse’ auxiliary roaring boats) in disembarking operations and light enough to be carried by crew men in river exploits.
This recently found example might as well be a XVI-XVII century local interpretation of a Manuelin berço.
Attached is of such examples, cast in Oriental India between mid XVI and end XVII centuries, with a diameter of 1,5 cms and a cannon length of 97 cms. (excluding the cascavel).
Their ammunition was generally a lead bullet or a bamboo tube filled with small shot.
Still the authenticity of the one found in Australia is something to be discussed. This type of cannons, having joined the Lantaka family, were later (XIX century) developed into distinct purposes, as either operational or passive versions, the late being widely used as currency (cannon money).
Those bearing such examples in their hands are in a better condition to judge their purpose and originality.
Let’s see what those museum curators say about it … if only caring for the truth and not fearing to shake history concepts.

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