A Detachment can only declare a Support Fire action if at least one model in the unit is armed with a missile weapon and the range between the charging unit and the Regimental Unit is greater than the charging unit’s Movement characteristic. If a Support Fire action is declared, the Detachment makes an immediate out of sequence shooting attack, resolved as if it had just declared a Stand and Shoot charge reaction against the charging unit. All unsaved Wounds from a Regimental Unit and its Detachment’s Stand and Shoot charge reaction and/or Support Fire actions, are combined when determining if the charging unit is required to take a Heavy Casualties Panic test.