Welcome to the Q&A Forum

thanks

thanks for this mr whippy

Another thing that affects the effectiveness of a 301 redirect, is the 'similarity' of the content (in machine terms, I'm talking about Boolean string similarity). If the content on both pages is highly similar (say, 75% similar) then most of the SEO authority will transfer across. If the content is not very similar at all, what you are doing is replacing 'proven' content with a new, unknown quantity which is a risk to Google. As such, the new content will have to prove itself