For six points, I wouldn’t even bother. Maybe if you were sitting on a half point toward a B, I could see you having a potential shot at convincing him.
As @lookingforward said, you would have to give him some kind of legitimate justification for bumping up your grade, otherwise it wouldn’t be fair to the other students who were probably 7, 5, 4, 3, or 2 points away from a B.