So, I have heard many people say before that it is difficult for some to agree to go to counseling or the doctor, because it is hard to admit depression.
If your husband is very resistant to counseling, there may be other things you can try to help him feel like he has better control over his life. For example, do you remember him doing anything for fun before this anger stuff started getting in the way? Let him know that it is OK, even imperative that he takes time to go hang out at the pool hall or bowling alley, or go for a hike, or go to the driving range, or take guitar lessons, or whatever it is that he likes to do (probably not the firing range though!). Encourage him to hang out with friends. Right now he has to take care of his mental health and it is even more important than spending time with family. Help him know he has more freedom than he thinks.
I feel like anger often comes (at least when I feel maddest myself!) from feeling like there isn't enough time to get things done. Taking time to help others and taking time to do something that counts as play are the two best ways (I find) to increase our perception of free time.
When he is at home, make sure to ask him to do things for you and the children (take out trash, read stories), and let him know you appreciate his help. He will start noticing that you don't miss him so much when he is away, so make sure you find ways to really need him while he is around. Hug him more and let him know how much his hugs mean to you.
So, those things might not be enough, but I just wanted to give you some options in case you find the prospect of getting him to the counselor insurmountable.