HTTP to HTTPS Google says to use 301 redirects

 HTTPS site migration use 301 redirects says Google

On a webmaster video hangout yesterday, Google trends analyst John Mueller strongly recommended that people migrating from HTTP to HTTPS do so with 301 redirects on a per-URL basis. He said you should not use other types of redirects, such as 303s or others; you should stick with 301 redirects for these migrations