Googler, JohnMu, said in a Google Webmaster Help thread that 410 status codes “generally” work faster in getting your content out of Google than a 404 status code.

Now, we knew using 410’s are more permanent but we did not know it would result in removing content from Google faster until now.

Google’s JohnMu said:

A 410 will generally result in us removing a URL faster from the index.

He does add that although 410s are almost permanent, they are not 100% permanent. John added, “we will generally retry 404s a bit more frequently than 410s, but we will still retry them especially when we find new links to those URLs.”

Forum discussion at Google Webmaster Help.