To all whom it may concern: Be it known that I, John M. BROWNING, citizen of the United States, residing in Ogden in the county of Weber and State of Utah have invented certain new and useful Improvements in Firearms, of which the following is a specification, reference being had to the accompanying drawings, forming a part hereof. The invention relates to automatic firearms of that description in which the several operations, as the opening of the breech after firing a shot, the ejection of the empty cartridge shell, the cocking of the hammer, is the presentation. and introduction of a loaded cartridge to the chamber of the barrel, and the closing and locking of the breech—are automatically effected through or by the energy of the recoil of the breech bolt or that part : which at the, time of firing the shot closes the breech of the barrel and the invention more especially relates to firearms of this description: winch, in firing, the barrel and the breech bolt are interlocked and recoil some distance together, and during this rearward movement the barrel has another movement imparted to it, Whereby it is unlocked from the breech bolt, and after its release the movements of the barrel are arrested, while the breech bolt continues to recoil until the breech is fully opened, and in which during the opening movement of the breech bolt energy is stored in a spring, the reaction of which is utilized to effect the return or closing movement of the breech bolt.
It is essential for the proper operation of firearms of this class that the breech bolt and the parts connected and moving with it should be made as heavy as practicable, so that it may store a maximum amount of energy in the short time during which on firing the rearward pressure of the powder gases in the barrel acts upon the breech bolt and initiates its recoil, mind so that the breech bolt nifty continue to recoil under its momentum alone to complete the opening of the breech and the compression of the reaction spring after the gas pressure has ceased because relieved by the exit of the bullet from the barrel. On account of the limited total weight practical for a small arm, and especially for a pistol, it is necessary in order to be able to give a maximum weight to the breech bolt, that the other parts of the, arm, the frame and the barrel, be constructed as light as possible.
This is especially important regarding the barrel of this class of arms, for the additional reason that at the commencing of the recoil the light barrel may readily yield to and move rear ward with the breech bolt while it remains interlocked therewith, and in order that when unlocked from the breech bolt, the movements of the barrel may be arrested, without causing by this sudden stopping in. jury to either the barrel or the frame of the arm. The main object of the present invention is to produce a firearm of this class which, in order to be specially adapted for the tary service, I be not only practical, efficient and perfectly safe in use, but strong and capable of withstanding the exposure and rough usage of service in the field and adapted to fire cartridges having bullets of large caliber and weight and powerful charges of powder; it shall also be very Simple in construction so as to be reliable under all conditions of service and not liable to get Out of order, inexpensive of manufacture, with a minimum number of parts; and readily dismounted and cleaned without requiring the use of any tools.
Another object of the invention is to produce a firearm of this .class in which to in sure the absolute safety of the user. the breech slide, comprising the breech bolt and the forward extension of the same covering the barrel, and the movable abutment enclosing the reaction spring shall be combined in one strong integral whole without a division or joint therein and shall be mounted upon the top of the frame from the front, to be so held and guided in its reciprocation thereon that it can be removed from the frame as one whole only and in the forward direction alone, by which the possibility of any part of the arm being thrown rearward shall be positively guarded against. Another object of the invention is to produce a firearm of this class in which the barrel shall first be seated ‘in the forward part of the breech slide, shall then be mounted with the breech slide upon the frame from ..the front, and finally the barrel shall be securely connected with and movably attached to the frame in ‘such a manner that the barrel may be at will and readily detached and disconnected from the frame, so that it can be removed from the frame with the breech slide in the forward direction only.