Get some A-Zoom snap caps, put a dime on top of the topstrap and dryfire away. If you can get about 7 trigger pulls without dropping the dime, you're getting somewhere. I had some probems with the boot grips myself, so I took an exacto knife and shaved away some of the corner of the grip that was rubbing away the skin. It sort of rounded the area out. Also try shooting with your thumb curved down.