303-redirect (how to)

your 303 redirect not many people use and in seo world its pretty dodgy you better of make a normal 301 redirect dude

What is a normal 301 redirect?
And how do I make that on my website?

You could do that with an instruction in a .htaccess file in your folder.
This site might help you out:
https://www.htaccessredirect.net/

Some background information:
https://support.google.com/webmasters/answer/93633?hl=en

It has nothing to do with the Responsive theme though.