I had a similar problem. Where the open end of the spring contacts the tang, the end of the spring wire got caught up in the opening and would not allow adjustment except in one direction. I had to arrive at a happy medium by turning the spring until it locked in but at a poundage that was satisfactory. I also screwed in a set screw to keep the spring from moving in use. Don't know if that helps your problem but its a start. I do know that it is possible to try to adjust the trigger too light and it won't set. Quick