My server returns this kind of header: Content-Range:0-10/0:

Additionally to Eugene Retunsky's answer, quoting from $http documentation regarding the response:
The response object has these properties:
data –
{string|Object}– The response body transformed with the transform functions.status –
{number}– HTTP status code of the response.headers –
{function([headerName])}– Header getter function.config –
{Object}– The configuration object that was used to generate the request.statusText –
{string}– HTTP status text of the response.
Please note that the argument callback order for $resource (v1.6) is not the same as above:
Success callback is called with
(value (Object|Array), responseHeaders (Function), status (number), statusText (string))arguments, where the value is the populated resource instance or collection object. The error callback is called with(httpResponse)argument.