This is a dangerous situation. All weapons should be kept locked up, and maybe you should be the one to hold the keys. As soon as possible get your son alone and ask him if your husband has ever weirded out on him when you have not been around. It's important for you to know the extent of the conflict between your husband and your son. Then if I were in your shoes, I'd have a calm discussion with your husband, when he is calm, and tell him that you were frightened and it's time to get some outside help with the situation -- then get to a counselor. Is your husband ex-military or a former police officer? Has he suffered a trauma in his past? The way you described the situation made me think it was not really your son your husband was seeing, but a flashback to a previous traumatic incident. I hope for the best for you and your family.