A common sight on fort walls and ship decks, this iron "pierrier à boîte", or breech-loading swivel gun, was in use from the early 15th century to the 19th century.
The mug-like receptacle at the breech could be removed and loaded with whatever fit in it, no ramming needed. As the name suggests, it could then easily swivel towards a target.
This specific model is not rigged - however, the gun itself, the fork on which it swivels, and the wooden post are available as separate prefabs, all with proper pivot placement to make it easy to position or rig if need be.
Four LODs per mesh will keep things light yet detailed up close.