netpea,
Have you asked him why
he thinks he's getting so angry so often? Maybe talking about it and having him ponder that for a bit would help... I know what you mean when you say it's hard to 'empathize with a kid who's gone ballistic'.

I've been there! It does seem as if there is no reason sometimes for what they are doing...but maybe you'll be able to draw that out. I know you have probably already tried this suggestion, but thought I'd mention it just in case.
Sometimes, too,
I have to take a look out how others in the household are behaving. Is he/she following the example of an older brother or sister (or mom or dad

), does the child feel left out or that no one listens....these are just things that have happened in
our house. When I worked in a private school a few years ago, I had a 3rd grade boy who seemed like he was always in trouble. When I talked to him one day, he said, "No on listens to me." I felt so bad for him...he felt that no one was listening so he had to take matters into his own hands. I tried to explain to him that if he would come to us (teachers)
first, maybe we would listen, because all we saw at that point was him hitting and punching and grabbing people....Anyway, these are just thoughts I had when reading the posts here. No accusations or anything like that.

We've all been there, I think. I hope this has been at least somewhat helpful.