We got the following problem:

• We changed all URLs on our page from oldURL.html to newURL.html and set up 301-redirects (ca. 600 URLs)
• Google re-crawled our page, indexed all the new URLs (newURL.html), but didn't crawl the old URLs (oldURL.html) again, as there were no internal links pointing at those domains anymore after the URL-change.
• This resulted in massive ranking-drops, etc. because (i) Google thought oldURL.html has exactly the same content as newURL, causing duplicate content issues, and (ii) Google did not transfer the juice from oldURL to newURL, because the 301-redirect was never noticed.
• Now we reset all internal Links to the old URLs again, which then redirect to the newURLs, in the hope that Google would re-crawl the pages, once there are internal links pointing at them.
• This is partially happening, but at a really low speed, so it would take multiple months to notice all-redirects. I guess, because Google thinks: "Aah, I already know oldURL.html, so no need to re-crawl it.

Possible solutions we thought of are ...

• Submitting as many of the old URLs to the index as possible via Webmaster Tools, to manually trigger a crawl. Doing that already
• Submitting a sitemap with all old URLs - but not sure if good idea, because Google does not seem to like 301-redirects in a sitemap
• ...

Both solutions are not perfect - and we cannot wait for three months, just to regain our old rankings. What are your ideas?

Best, David