Viewing raw RSS feed?
A solution that doesn't require using different browsers:
In Firefox preferences, select Applications and search for "Web Feeds." Changing the action to "Preview in Firefox" allows Firefox to load the feed itself, instead of google reader. It has a "gussied up" display of the feed in the browser, but you can also view the source to see the actual text of the feed.
You can use a difference broswer, though most browsers will apply an xsl stylesheet to raw feed data by detecting that its a feed using the http response content type header. I know that Google Chrome shows some kind of raw data for rss feeds though its not exactly pure xml.
You can Use Fiddler to see the response. Or use some other http sniffer tool.