Reusing content after 301 redirect?

Basically I want to know if I can reuse the content that I've 301ed to a new site?

I have 2 websites with very similar content, so much so that I can 301 an article on site A to an article on site B that's optimized for the same keyword. But besides being optimized for the same keyword, they are entirely different articles. So I'm thinking that once the article on site A is 301ed away, it's now de-indexed - meaning I should be able to use this article on a site C without penalty?