thanks for answering and clarifying, I fixed my code not long before you answered.
I guess there is no better way to do it.
here it is:
Vector3 rotDeg = scopePiv.RotationDegrees;
rotDeg.y = Mathf.Clamp(rotDeg.y, -100.0f, 100.0f);
rotDeg.x = Mathf.Clamp(rotDeg.x, -40.0f, 40.0f);
scopePiv.RotationDegrees = rotDeg;