320 movement is the cancellation of 319
319 Split structured material into components (Retail)
I am not on retail, so I cannot tell if 319 is designed for special stock. Looking at the predefined movements in WM, I tend to so it is not allowed to split consignment stock.
the help does as well not mention any special stock: http://help.sap.com/saphelp_40b/helpdata/ru/fc/6cec6eb435d1118b3f0060b03ca329/content.htm