i would probably narrow that down to 4 points. 4 points is out of the expected range of error using practice tests as predictive diagnostic tools (assuming a +/-3 point window, on average). If you are consistenly out of your window, then you are very likely to end up with a lower score then you expected.
You are certainly not ready for the actual test if you don't have a target score and really good sense of whether or not that score is achievable based on practice test history.