Old medieval Cannon Mortar with pbr textures Low-poly (Polygon mesh 3D model) is available on CGTrader for $3. Original author: esmilesvfx.
STL (Stereolithography, filesize: 379 KB), OBJ (OBJ, filesize: 500 KB), DAE (Collada, filesize: 384 KB), BLEND (Blender, filesize: 1.77 MB), ABC (Alembic, filesize: 1.27 MB), FBX (Autodesk FBX, filesize: 250 KB), GLTF (glTF, filesize: 20.8 MB)