What is the company that you work for, like what do you make or do that allows him to do such things.
Take pictures of all your wounds, bruises, etc and make a scrap book or post them in his office to show the abuse you are taking.
It sounds like something happened in his life to cause him to "snap" and his only outlet is the workers. You could sue him technically for abuse, each of you leave a note or letter about how you are terrified of getting shot at, that it makes you feel unsafe to come to work, that you like working there but getting shot at causes the safety levels to drop severely and makes you afraid of him in the abusive way. Show what hes done, shooting back at him with may cause you to lose the job rather than keep it.