Hi Willow~
My husband is BiPolar (BP). He has occasional rages. They are difficult to endure. I have been dealing with them for about ten years ...
Since your son is 16 I would imagine that he is just too large for you to do anything physically. I wouldn't recommend it.
I would suggest to 'walk away'. Leave the house. Go into a bedroom and shut the door. Don't respond.
IF your son is in danger of self harm ... or if your physical safety is threatened I would call the police or an ambulance. There are no other alternatives.
I had to call an ambulance once. But, I had to do it.
I would talk with your son when he is in one of his 'compliant and sweet' moods and explain your plan of action the next time he rages.
It puts the ball in his court. It provides you with an 'out' in the event that he just can't pull himself together.
doesn't it??