Patent ID: 7798044

Claim:
A weapon system comprising: a barrel for accommodating a projectile in a breech end portion thereof prior to firing and having a muzzle end portion out of which said projectile can be fired; a breech block for closing the breech end portion of the barrel when said projectile is accommodated in the breech end portion and for opening the breech end portion after said projectile has been fired; and a device for purging the barrel comprising: a slot through which pressurised gas flows radially inwardly into the barrel; a profile shaped to incur the coanda effect, the profile provided downstream of the slot, the profile curving in a direction towards the muzzle end portion so as to direct the flow of the pressurised gas from the slot into the barrel outwardly through the muzzle end portion; a source of pressurised gas; and a duct which connects the source of pressurised gas to the slot so that pressurised gas can be selectively supplied to the slot and along the profile thereby entraining air in the barrel and exhausting debris and/or fumes outwardly through the muzzle end portion after firing of said projectile; wherein the weapon system further comprises a sensor for sensing when said breech block is opened, wherein said pressurized gas can be supplied to the slot dependent on when said sensor senses that said breech block is opened.