Delayed blowback firearms with novel mechanisms for control of recoil and muzzle climb

Abstract

The mechanism comprises a main frame ( 1 ) and its extension ( 1 ′), which accommodate a barrel ( 21 ) with fixed mounting, a mobile bolt ( 22 ) and its guiding pin ensemble ( 66 ) and main spring ( 67 ) moving in the main frame ( 1 ), a mobile mass ( 34 ) and its assembly of guiding pin ( 60 ), push plate ( 61 ) and return spring ( 62 ), and a mobile mass catch sear ( 42 ) and its spring ( 7 ). The mobile mass pivots from a first position under the barrel to a downward position in reaction to the backward movement of the mobile bolt. The placement of the mobile mass in front of the chamber directs counteracting forces down on the barrel to prevent muzzle climb during operation.

1 . A method of designing of firearm, the firearm comprising a counteracting mobile mass configured to move in reaction to firing and to counter the recoil forces upon firing, the firearm further comprising:
 a barrel with a cartridge chambering end and a firing end;   a mobile bolt configured to move along the axis of the barrel from forward to rearward and a rearward to forward position during operation of the firearm;   a mobile mass configured to pivot from a upward and cocked position under the barrel to a lower position and having a surface to contact the mobile bolt during its movement;   a receiver comprising a top main frame part configured to allow the movement of the mobile mass from a forward-most cocked position to a rearward position while confining the mobile bolt within the axis of the barrel, the top main frame part of the receiver further comprising a forward extension assembly for fixing a barrel and for connecting the mobile mass below the barrel and forward of the chambering end of the barrel, the connection to the mobile mass allowing the mobile mass to pivot,   wherein the mobile bolt comprises a projection that contacts the mobile mass at a first angled surface of the mobile mass, and upon firing of the firearm directs the pivoting movement of the mobile mass downward away from the barrel and wherein the downward movement of the mobile mass counteracts the recoil forces upon firing,   
       the method comprising selecting a caliber for the firearm and modifying the angle of the contact surfaces between the mobile bolt and the first angled surface of the mobile mass in relation to the longitudinal axis of the barrel is modified according to the choice of caliber of the firearm. 
     
     
         2 . The method of  claim 1 , wherein the modification of the contact surfaces further includes a selection of a desired firing rate of the firearm.