The angle of the flyer seems to indicate that the barrel may be touching wood upon vibration. Just because a dollar bill can be slipped between barrel and forend, it doesn't mean that the barrel isn't bouncing off when vibrating at the shot.
You should have at LEAST 1/16" of clearance when free-floating. Also, if you increase stock screw tightness and wood compresses, it reduces clearance you may previously have had.
