Improvements in Automatic Fire Arms

14,746. Orman, B. June 24. Breech actions, sliding barrel and breechblock.-Relates to automatic guns in which the barrel and breech-bolt recoil together for a short distance and then become unlocked by the movement of a rotary head, the breech-bolt being made in two parts connected by a quickthreaded stem so that the rotary unlocking and locking movements of the bolt-head are caused by the bolt-body sliding on the stem during the initial opening and the final closing of the breech. The present invention consists mainly in so arranging the bolt that the rearward movement of the bolt-body is accelerated by suitable means during the short recoil of the barrel. In the construction shown in Fig. 4, this acceleration is caused by a lever a pivoted to the barrel extension. The lower end a of this lever bears against a fixed shoulder on the gun frame, and the upper end engages the front of the bolt-body B. The barrel extension is formed with two rearward guide-bars a , Fig. 10, on which the bolt slides, the guiding-surfaces being the top and outer edges of these bars. The inner edges are shaped to control the feeding of the cartridges, as only at the forward part is the opening between them wide enough to allow the cartridges to pass. The ejector a is formed on one of these bars. The extractor b , Fig. 5, is formed integral with a spring collar b which secures it in position on the bolt-head. A safety-lever K, Fig. 4, is adapted to be turned down by an external thumb-lever k to block the movement of the trigger.