======Calculator for the effective cross-section====== 
{{ en:media::aeffcalculator.png?35%&link}}  This tool or assistant, helps in calculating the effective cross-sectional area of a caliber or barrel based on your own measurments. Effective cross-section means the physically effective area of the projectile on which the combustion pressure acts while the projectile is moving through the barrel.  

**The effective cross-section** is in many cases specified by the standardization body / organization (e.g. CIP). In this case, the value given by the caliber specification can deviate from the result calculated with this assistant.  

An adjustment to actual measurements, for example the dimensions for a polygon barrel or the individual number of grooves in your guns barrel, will improve the calculated results.  

If started from the current load **via the star symbol **, the assistants input fields are automatically prefilled with values matching the selected caliber specification (see picture above).