do you shoot a vertical line when shooting at 10, 15, 20, 25, 30, 35, 40 ?????? if not your biscuit might need to be moved left or right..though it sounds to me like you need to move it right..tape a vertical line on the target and shoot from those distances...if it shoots a line like \ then you need to move yourrest right...i think you need to tune in your left and rights on your rest then worry about your sight moving