You do not have a bad score of 427. You can drastically improve your score with below magic numbers in IELTS.
Minimum IELTS score: L-8, R-7, W-7, S-7. (This gives you 50 additional points called Adaptability)
Maximum IELTS score: L-8.5, R-8, W-7.5, S-7.5 (This will give you the highest points...