I don't know anything about guns or hunting but I heard on the news early this morning that it was a deer rifle with a scope. Some idiot is trying to spin this into a gun ban by saying it was an assault rifle.
The AP on Yahoo is reporting it was an "SKS semi-automatic rifle" a "typical" gun for hunting.
You can see the video linked from the Yahoo story here:
http://story.news.yahoo.com/news?tmpl=story&cid=519&ncid=716&e=5&u=/ap/20041122/ap_on_re_us/hunters_shot
The link for the AP video is next to the third picture down on the left hand side.