20,455. Frommer, R. Sept. 13. Breech actions, sliding barrel and breech-block.- In an automatic gun which by turning a single lever can be adjusted for hand - operation, the arrangement is such that when adjusted for automatic action the handle is disconnected from the breech-block, and when adjusted for hand operation the barrel is locked, the handle is connected to the breech-block, and the return spring is disconnected. The parts are so constructed that the converting movement can only take place when the breech is closed, and the gun cannot be fired when the converting-lever is in an intermediate position. Fig. 1 is a sectional elevation of a rifle embodying the invention, Fig. 2 a sectional plan, Fig. 3 a section on the line III-IV in Fig. 2, and Fig. 7 is a rear elevation. The breech-block 1 is connected to one of two sliding rods 5, 10, one of which is operated by the handle 4 and the other 10, in the closing direction, by the return spring 9. These rods are mounted so that they can rotate, and are geared together, preferably by means of a cranked lever 19, Fig. 3, having toothed ends, so that rotation of one causes a corresponding rotation of the other. At the rear end, each rod has a projecting lug 6, 12 which on rotation engages or disengages a recess 2, 3 in the breech-block ; when one is engaged the other is disengaged. The rods are rotated either by turning the handle. 4 up or down, or by turning a lever 26 at the rear of the gun. The lever 26 is coupled to the rod 10 by an intermediate tube 24. A spring catch 27 locks the lever 26 in one or other of its extreme positions. In the position shown in Fig. 3, the gun is adjusted for hand operation and one arm of the lever enters a slot 22 in the barrel to lock it. To ensure that the lever 19 is kept locked when the rod 10 is drawn back, there is provided in.front of the rod 10 a spring plunger 33, Figs. 1 and 2, having a notch 34 which engages a tooth 35 on the lever 19. When the bar 10 is in the forward position, the plunger 33 is pushed out of engagement. To prevent the converting movement from being made except when the breech is closed, a stud 42, Fig. 2, on the breech-block engages a slot 41 in the tube 24, the slot having a cross cut 43 at the point where the tooth fits when the breech is closed. In an alternative construction, a stud on the tube 24 fits a groove in the breech-block. To prevent firing from taking place except when the converting movement has been completed, the lever 26 is fitted with a segment 38, Figs. 1, 2, and 7, which in any intermediate position engages a groove 39 in the firing-pin. The segment is bevelled at the ends so that the firing-pin is slightly drawn back to allow the sear to re-engage if the trigger has been pulled and then released.