bones...
if you want to see bones in W3Dview, you cant

. however, if u have the W3D importer addon for gmax/renx, then u can (obviously) import the w3d into gmax format. in gmax format, u will notice little spheres that u dont see in the w3dview. those are your special bones. they have speical names, and are used as the invisible starting points of things like lighting, dust trails, smoke, etc
if u want ur turret to turn, just call the mesh Turret and make sure it is defined in the appropriate object INI.