A breech system for a firearm exhibits a breech which can be locked in its movement in the barrel block by at least one locking element, which is pressed against the rear end of the barrel by means of a breech spring surrounding the rigid barrel of the weapon, the barrel being enclosed with the exception of the front and rear apertures, whereby the breech spring is supported at the rear section of the barrel and at least one link element subjected to tension connects the front end of the breech spring and the breech. In order to guarantee precise function and in a manner which is safe for the user, by means of a simple arrangement which is reproducible in manufacture, a purely mechanical delay element is inserted in the link between the breech (10) and the breech spring (9).