Shitty situation, but you made a good call.

It’s important that he learns a lesson from this. What happens if he points it at someone who is left traumatized? What if he points it at someone who’s armed, and shoots him? Pointing realistic fake weapons at people, without explanation, isn’t an acceptable thing to do.

He’s feeling negative emotions and taking it out on others. Not your problem. If he’s any sort of decent person, he’ll be able to see that he was being a dick, and the friendship will be fine.