ok... just got caught up on this thread... Early on, I had some back and forth with pdib on the spring. I initially swapped out my spring for a BeCu one I had laying around. I got an improvement in test results. What was going on (what I believe was going on) was how the button was being pushed. I think Turbo hit directly on this point. Its not that the device wasnt conductive, it was how the electrons were flowing. If I didnt get good contact with the aluminum bolt to copper plate, current was traveling through the steel spring. So, I needed to adjust how I was pushing the button (a little bit off to side). When I put the BeCu spring in, it didnt matter how I pushed the button, all current paths were happy.
My OliveR just turned 3 (months old), so I bought him a present (BFCyclone with AFC). I also made him a matching traveling cap.