What is the Handicap for?
The handicap is a seldom used feature. It is calculated as 80% of your missed targets. If you have an average of 60% then you are missing 40%.
80% of 40 is 32. Your handicap is 32
A handicap score is an option for some promoters at some shoots. For example, at some (but not all) Alberta Provincial Championships, there is an award for High Handicap score. The CNSCA awarded a High Handicap Score award at the 2014 National Championships but not at the 2016 championships.
An award for High Handicap score puts all shooters from Master class to E class on a more even playing field with every shooter having equal opportunity to be recognized for turning in a “best performance relative to their known ability”.
It could also be used to calculate a Calcutta, assuming all participants had an established handicap (i.e. hunter class and new shooters would not have an established handicap).