Update: Blogger changed something and the work around I gave in this post no longer work.
I have a test (and demonstation) Blogger private blog Peter's Private Blog which is also used to demonstrate how one can make provision for visitors to request for an invitation to the private blog.
Now I want to test if it is possible to read the content of that Blogger private blog using feed and Google Reader. I signed into Google Reader, click "Add subscription", then typed "http://peters-private-blog.blogspot.com/feeds/posts/default?alt=rss" into the "Add subscription" box. When I click "Add", I got the error message:
[No feed available for "http://peters-private-blog.blogspot.com/feeds/posts/default?alt=rss"]
This is despite the fact the the feed option had been set to "Full". This test shows that it is not possible to read the content of a Blogger private blog using Google Reader.