I'm sorry, now that I look through the numbers much more carefully it seems our results may not be too far off. The last two or three tests I did didn't include the lead equivalent to 9.5mm but depending on a few things they've usually been around 30 fps apart, about 40 fps with much higher elongation.
Plus, with all those fun numbers in one place it's likely I may have misread something. Also, thank you for all the information. Numbers are like candy for the mind