How are these brakes so good?

[smilebigtt]

Put the brake shoes and hardware on the front. Operation the brake lever by hand, the shoes barely spread. The wedge and wheels seem to be are in good order.
1. With the upper part of the shoes basicly strationary expect for adjusting, how do you get more then the bottom 1/4 shoe to make contact with the drum? Do the brakes have to run so close to the drum that this seeming minor movement is enough to apply enough brake to stop the truck?
2. How much free play should there be between the brake activator and when it first makes contact with the push pin. The pin that goes down to the brake wedge? On the driver side I have close to an inch of free travel. On the rider side I have maybe a half inch of free travel. I understand I adjust the brake rods to take up slack in the system but should the two activators have a closer free travel then this? Do I adjust this by adding shim in the wedge where the pin socket is? If so, how many shims is too many shims?
Thank you. ty