301 Redirects can take a while to register with the search engines, but the wait is worth it
This article references a roundtable of SEO experts answering the "How long does it take to update site-wide 301 redirects in Google?" question:
"So lets say you change all of your urls on your website to a completely new url structure. You 301 redirect all the old urls to the new ones. So how does it take for this to update in Google and other search engines?" source
Sometimes it could take up to a year to update your site in the SEs; in practice (with Google anyway) its usually < 6 months.
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