So, since this is all Space Marine focused, I just thought that I would get peoples' opinion as to the longevity of Marines. So, err, yeah. That's the question. In your own particularly interpretation of the 40k universe, are Marines immortal (ala the Horus Heresy novels)? Do they have a lesser lifespan and, if so, what is that lifespan and how did you come to use those particular values?
My interest stems out of writing this up for a little fan supplement wherein I tried to create a value that is balanced between the extremes (several hundred years versus immortal... sorry, unaging).
Oh, if you post a reference to the background, feel free to add a citation. It's always nice to see where things come from. 
Kage

