complete the travel of its toggle mechanism sufficient to move the center pin of the toggle and force it to complete its downward travel to its lowest point down inside the handle of the gun against the bias of its compression spring shown in fig2 of this patent the inertia of the bolt continues rearwardly compressing the recoil compression spring of this patent until the end of the lug engages a stop surface of the frame of the weapon the bolt and toggle are returned to their original positions by the stored up energy in its two springs this completes the firing cycle and prepares the gun for the second firing having picked up an additional bullet from the clip magazine and placed it in the chamber when the bolt returned to its original position by well known conventional mechanism the mechanism disclosed and claimed herein to serve the function of spring 61 of u s pat no 3 630 119 has been eliminated and the braking system shown in fig1 21 substituted therefor this braking system as shown in fig1 15 and 21 compress a brake shoe 70 pivotally mounted to frame 25 of the weapon and adjustably arranged adjacent edge 25a of frame 25 as shown in fig1 and biased by spring 71 into the path of movement of bolt 34 in frame 25 upon collapsing of the toggle 38 39 under the recoil of an exploding bullet the end 34a of the bolt 34 will engage surface 70a of the brake shoe and force it to compress spring 71 as it pivotally moves back into cavity 72 in the bore.