Maybe its the way I wrote the posts. It may take a few posts to straighten out.

The dimensions of the springs were used to calculate the spring rates. That's where all of the spring rates posted come from. I do have a few springs with rates from the manufacturer but did not post those. But they back up the general accuracy of the calculated rates.

In the post immediately above, the numbers in the two right hand columns represent spring force. Pounds force.
This is the force of each spring pulling on the weight.

With the wieghts engage into the advance slots, the primary spring is slightly stretched.
So it provides a restraining force on the wieght.
That force(red arrow) is the spring rate multiplied by distance stretched.
.79"-.72" = 0.07" stretched
8 lbs/in x .07" = .56 lbs force
The secondary spring is free to move, so it applies no force.