It's a rank based on forum usage, the ranks progress through stages according to post count. Repalce the word "hunter" with "poster" and they make more sense, but seeing as the forum is called "Hunting Life" it's fair to say that those on here are hunters (or certainly think they are).
I've encountered a lot of "chairgunners" in my time. Anybody can whack up 3000+ posts by saying things like "nice pics mate" and "cracking" but others prefer to seek help or provide answeres, sometimes wit ha little banter or chat thrown in for good measure.
I've been on here to ask for tips and advice