I am not (yet) qualified to make a decision on this, but what are your thoughts of advertising on http://www.theboxotruth.com?
It appears they run tests on various rifles and rounds, so I don't see a problem with it myself...if it's FREE. I would explain to them that we are a grassroots, all volunteer organization, not for profit. Teaching people how to safely and effectively use rifles is a part of what we do. We have a banner you could submit if they would allow it. We can't reciprocate on links or banners though; some sites require this. Good luck! :)