Hi blk91stealth,
GMAC has publicly stated that the Official Score that you earn on Test Day is within +/- 30 points of actual ability. By extension, this means that you could have easily scored 500 on your Official GMAT, but you likely made a few too many little mistakes that cost you those points.
With your score goal, you don't have to correctly answer ANY of the hard/weird questions that you see on Test Day, BUT you have to keep the little mistakes to a minimum. When you reviewed those practice CAT results, how many questions did you end up getting wrong because of a silly/little mistake? THOSE mistakes are what cost you the points that you were looking for.
In real basic terms, you have to work in a more precise way (take more/better notes, do organized work) and take advantage of the fact that you can afford to 'dump' the hard questions you face (just take a guess and move on).
1) When are you planning to retake the GMAT?
GMAT assassins aren't born, they're made,
Rich