Hit detection with unity character controler

I am making an FPS game using stickmen as characters (example : http://stickmanplayer.com/wp-content/uploads/2013/03/Stick_Man.jpg , but 3D ofc) and I am using the unity FPS character controler. How do i detect that i hit the character himself? The unity character controler has it's own collider (capsule collider). Any other colliders i add to it's children seem to be ignored ( for example the gun is outside the capsule collider, so i added a new one to it, but it's ignored when i walk into a wall for example).