Don't shoot until your PH (and only your PH) tells you to do so. Last year I had a client take three quick shots with his muzzle braked 416 blaser while I was assessing the trophy........ at the time my head was about 18 inches from and in line with the end of the barrel and my hands were full of binos........ My hearing in that ear now comes and goes and it often feels like I have my head in a galvanised bucket...... I haven't been to a doctor about it as I don't reckon I need one to tell me my hearings buggered...... but I'd estimate I've lost at least 30% of my hearing in that ear.

Oh yes, one other thing........ don't forget to speak up when you talk to your PH........