I thought I would get 75%. One shot went wildly off course. The sky was so full of Migs the seeker locked onto a different Mig! 
  
I'm running on the May patch, so I don't know the advantages/disadvantages of it compared to others. But I'm really picky about firing parameters with the AIM-9. With every kill, the Mig was in a shallow turn (NOT pulling hard) and at low E so a violent maneuver wasn't likely. Usually, I was between 1.0 and 0.7 range. Shorter than that, I often get a miss, longer than that and the Mig has enough time to react, and it's a miss. I don't ALWAYS get 100%, but I do pretty well. Even with AIM-9D, I'm managing 50% pretty often.