My DS has an explosive temper. There is another child being horrible to him at school (he is 5) so he lets it out at home.
We are working on different techniques to support him. Before we leave the school, make sure there isn't anything he needs to tell us, that we then need to address with the teacher.
While I dislike doing it, bring carrot sticks or another snack with us, when picking him up helps.
Giving him half an hour to do what he wants, to wind down after school.
Also watching things he has snack wise. Some things set him off climbing the walls, other things seem to make him angry. I can't find anything in them specific enough to say this is it, but sugary stuff plays a part, (maybe E numbers)
Also as a child I had a very explosive temper, it took me years (late 20's) to manage it well, we use time outs a lot, not just for him, but for me. We take a few minutes to calm down and then talk, first him then me, taking turns and listening to each other.
Things we have found haven't work, threatening to take a toy away and following through on that, he didn't seem to mind. Not following through on something, this set us back a few weeks. Reward jar.
I personally think it is a long road, and while we have been working on it for 3-4 months now, his temper has gotten better, although when he does lose it, he still goes for it, however he has stopped trying to hit or hurt me