The breechblock is closed or locked by a continuous movement of the operating lever. When the block is swung to the closed position the front face of the block latch comes in contact with the rear face of the breech of the gun, thus forcing the latch out of the notch in the breechblock and back into a recess in the carrier. By continuing the motion of closing the mechanism, the breechblock is then rotated on the hub of the carrier and its threads engage with corresponding ones in the gun. When the breechblock is in the closed position, a lug on the firing-lock case serves to lock the carrier to the breechblock and prevents displacement due to a blowback. =The firing mechanism= belongs to that type known as a continuous-pull mechanism; that is, no cocking of the firing-pin is required. =The firing-lock= case is eccentrically fitted in the hub of the block carrier, in such a position that the axis of the firing-pin is always in line with the bore of the gun. The vent bushing in the front end of the breech block through which the firing pin passes when in the fired position, is fitted eccentrically with reference to the breechblock. This eccentric arrangement of the breechblock, masks the point of the firing-pin and prevents any possible contact between the pin and the primer in the cartridge case when the block is unlocked. The block will be practically fully locked before any contact between the firing-pin and primer can take place. Nomenclature of important parts of Breech & Firing Mechanism. Mod. 1905:—