You are going to get some noticeable heat mirage looking through that scope as soon as the barrel heats up. The barrel isn't going to whip 1/16 of an inch at the shank and make contact with the bell, but you aren't leaving much room for general forgiveness. I would put it higher, but part of that is personal preference for comfort getting behind the scope because of my high cheek bones. Obviously everybody's face is different, but I would give yourself a little more room to work, especially if you will be shooting from different positions.