My purpose is not to alarm you needlessly but I would strongly encourage you to seek counseling for your son immediately. His anger and rage are out of control and no amount of spankings and restrictions are going to help him cope with these intense negative feelings and a possible/probable need to act on them in an increasingly violent fashion. Your hitting him and punishing him will only serve to further inflame his rage and strengthen his resolve to hurt others.
He has talked to kids about wanting to shoot other students. He has brought a bullet to school and expressed a desire to have a gun. Just because he said "cap gun" as opposed to 22 caliber gun offers one no relief. He is obsessed with violence and cannot control himself. His school should be made aware of his threats, as they may need to take action to protect their student body.
Lori, this is very serious business and you need professional help right now to deal with your son's rage and potential for violence. Please enlist the support of friends, family and the school system to get your son the help that he desperately needs. You may think that my response is an exaggerated one. I don't think that the parents of the boys who murdered other children or the parents of the kids that they murdered would find my reply to be overly dramatic. Write back if you would like a further reply.