I'm not sure how to duplicate the main content of the Loader. However, a reasonable workaround might be to load the SWF bytes once and create multiple Loaders from those bytes:
Load your SWF bytes with a URLLoader:
var urlloader : URLLoader = new URLLoader(); urlloader.load(new URLRequest("your url here"));
Once it is loaded, use the bytes to instantiate new display objects:
var loader : Loader = new Loader(); loader.loadBytes(urlloader.bytes);
Use your loaded loader's loader.content display object on the display list (or the loader itself).