Here, a great study about burned calories during thre exercises.
I think that the first concept is the mos important:
“Calories burned during exercise is affected by body weight, intensity of workout, conditioning level and metabolism.”
So what could be the average if your are a boxer? and keeping in mind if you body weight is for example155 Lbs or 75 Kg?
In the Ring 844 by hour
Knocking the punching bag 422 by hour
Making Sparring 633 by hour
So what do you waiting for?