These arrows aren't stiff enough for a bow that heavy. Not sure why the first ones worked and the second ones didn't; but the draw weight range for 2117 at 30" with a 100 gr. tip is 47 to 52 lbs. For a 64 lb. bow, you should be using 2315, 2219, or 2415 Easton aluminum arrow - at 30" with a 100 gr. point.