Was at an outdoor CQB game and had set myself up in some hay bales to guard the rear entrance to the building we were defending. Every time one of the OpFor came around back I waited till they were at 15 ' from the door (I was about 50 feet away at 90 degrees to the door) I'd pop them (double tap). They would look around saying "where the F@#$ did that come from". They were convinced it was someone inside the building shooting out at them. Got many kills that game.
Nothing says loving, like a head shot!