Gas Operating System for Low Energy Ammunition

This application is a continuation of U.S. patent application Ser. No. 18/415,988 filed Jan. 18, 2024 which claims the benefit of U.S. Provisional Application No. 63/480,475, filed Jan. 18, 2023, which are both hereby incorporated by reference.

This disclosure relates to the field of gas operating systems for firearms using low energy ammunition such as pistol caliber ammunition.

Automatic and semi-automatic weapons have employed a variety of gas-operated systems utilizing the pressure of combustion gases released upon firing of a round to engage and displace a bolt mechanism to unlock, extract, eject, feed, reload, lock and cock before firing the next round. Many of the prior art systems employ a piston-cylinder arrangement mounted parallel with the gun barrel. Other prior art systems employ direct impingement of combustion gasses against the bolt mechanism. Either way, a gas operating system used with low energy ammunition, such as pistol caliber ammunition, can have more failures to adequately cycle compared to similar systems that use high energy ammunition, such as rifle caliber ammunition, due to comparatively lower combustion gas pressure and potentially greater variability in combustion gas pressure between different loads of the same caliber ammunition.

There is also a desire to convert firearm platforms originally designed for rifle caliber ammunition to use pistol caliber ammunition. Pistol caliber ammunition is generally less expensive than rifle caliber ammunition. In addition, pistol caliber ammunition can be lighter than rifle caliber ammunition. Furthermore, if a firearm uses a suppressor and subsonic ammunition, pistol caliber ammunition can be configured for this application due to generally lower bullet velocities and generally larger diameter rounds.

There is a need for gas operating systems operable with low energy ammunition.

For the purpose of promoting an understanding of the principles of the claimed invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the claimed invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the claimed invention as described herein are contemplated as would normally occur to one skilled in the art to which the claimed invention relates. Embodiments of the claimed invention are shown in detail, although it will be apparent to those skilled in the relevant art that some features that are not relevant to the present claimed invention may not be shown for the sake of clarity.

With respect to the specification and claims, it should be noted that the singular forms “a”, “an”, “the”, and the like include plural referents unless expressly discussed otherwise. As an illustration, references to “a device” or “the device” include one or more of such devices and equivalents thereof. It also should be noted that directional terms, such as “left”, “right”, “up”, “down”, “top”, “bottom”, and the like, are used herein solely for the convenience of the reader in order to aid in the reader's understanding of the illustrated embodiments, and it is not the intent that the use of these directional terms in any manner limit the described, illustrated, and/or claimed features to a specific direction and/or orientation.

A gas operating system for automatic cycling of a firearm using lower energy ammunition such as pistol-caliber ammunition is disclosed. The disclosed system may be configured to utilize gas produced by combustion of cartridge propellant to automatically cycle the firearm. To that end, and in accordance with some embodiments, the disclosed system includes a gas block which routes high-pressure gas from the barrel through a gas port to either a piston or to the bolt. The location of the gas port may be selected to lie within a region of the barrel which generally corresponding with declining pressure after the peak of the pressure curve associated with a given pistol cartridge. The high-pressure gas may impinge on either the piston head, forcing the piston rearward and into physical contact with an operating rod that moves to the bolt carrier, or directly against the bolt carrier of the firearm. Consequently, the bolt carrier may be driven rearward, allowing for cycling of the firearm to progress.

The disclosed gas operating system can be configured, in accordance with some embodiments, to be compatible for use with a wide range of pistol cartridges, including, but not limited to, 0.380 ACP, 9 mm caliber (9×19 mm); .357 caliber; .40 caliber (10×22 mm) and/or 0.45 ACP. The disclosed gas operating system can also be used with cartridges that have been loaded to fire subsonic projectiles, for example the 300 AAC Blackout (7.62×35 mm) and any of the above caliber cartridges loaded as subsonic ammunition. The disclosed gas operating system is configured, for example, to utilize a volume of gas for cycling a firearm that is less than that produced by a supersonic rifle cartridge, such as the 7.62×39 mm or 5.56×45 mm.

The disclosed gas operating system can be configured, for example, as: (1) a partially/completely assembled gas operating system unit; (2) a completely assembled firearm integrating such unit; and/or (3) a kit or other collection of discrete components (e.g., barrel, gas block, piston, gas regulator assembly, operating rod, etc.) which may be operatively coupled as desired to provide a firearm with automatic firing capabilities.

Referring to, assemblyis illustrated. Assemblygenerally includes barrel assemblyand gas block assembly. Barrel assemblygenerally includes barrel, barrel extensionand flash hider. Gas block assemblygenerally includes sleeve, sleeve, clipand tube.

Referring to, barreland barrel extensionare illustrated. Barreldefines ports, breech face, slotsand bore. Barrelalso generally includes outside surface, and threadsand. Portsextend between boreand outside surfaceof barrel. Portsare positioned distance Dfrom breech face. Breech faceis the position of the face of the bolt face (not illustrated) when firing. The illustrated embodiment includes 3 ports. In the illustrated embodiment, portseach have a diameter of approximately 0.067″ (1.7 mm). Fewer or additional portshaving larger or smaller sizes can be used as desired to achieve the desired venting of gasses from boreas described below. For example, 2 portsor 4 portsor 5 ports.

Referring to, sleeveis illustrated. Sleevegenerally defines bore, groove,and, slotand outside surface. Boreis configured to fit around outside surfaceof barrel. Grooveis configured to receive clipwith slotallowing clipto engage sloton barrelto secure sleevein position relative to barrel. Grooveis configured to receive a sealing member such as an O-ring (not illustrated) to seal the gap between boreon sleeveand sleeve. Grooveis configured to receive a sealing member such as an O-ring (not illustrated) to seal the gap between boreand outside surfaceof barrel.

Referring to, sleeveis illustrated. Sleevegenerally defines bore, groove, boreand bore. Boreis configured to fit around outside surfaceof barrel. Boreis configured to fit around outside surfaceof sleeve. Grooveis configured to receive a sealing member such as an O-ring (not illustrated) to seal the gap between boreand outside surfaceof barrel. Boreis configured to receive tube. Boremay also optionally be configured to receive a piston (not illustrated).

Sleevesandtogether define a gas flow passage between portsand borethat directs combustion gasses to tubeto cycle the bolt carrier using either direct gas impingement or an operating rod, as known in the art.

Referring to, a plot of pressure vs. barrel position for a 9 mm cartridge is illustrated. The x-axis is the distance in the barrel from the breech face, in inches, and is equivalent to distance D. The y-axis is the chamber pressure in psi. Line Z is the pressure at a particular barrel position. A second y-axis indicates the velocity, in feet per second, of the projectile as it passes through the barrel. Line Q is the velocity at a particular barrel position. Maximum chamber pressure M is approximately 34,000 psi, which occurs at approximately 0.9 inches (23 mm) from the breech face.

In the illustrated embodiment, distance Dis approximately 1.75 inches (44 mm). The position of portspositioned at 1.75 inches (44 mm) is indicated as point A. At point A, the chamber pressure is approximately 18,000 psi, approximately 53% of maximum chamber pressure M. At point A, the slope of line z is approximately 70 degrees. Applicants have determined that at point A the variability between different loads is reduced while sufficient energy is still available to cycle the weapon. Applicants have found that venting too close to maximum chamber pressure M is problematic because there can be significant variance in maximum chamber pressure in different loads. Conversely, Applicants have determined that venting too far from maximum chamber pressure M can provide insufficient energy to reliable cycle the weapon. Applicants have determined that venting between approximately 90% of maximum chamber pressure M and 40% of maximum chamber pressure M provides an acceptable balance between reduced variably between loads while retaining sufficient energy to reliably cycle the weapon.

illustrates various locations in this range. At point B, distance Dis approximately 1 inch (25 mm), chamber pressure is approximately 30,600 psi, approximately 90% of maximum chamber pressure M. At point B, the slope of line z is approximately 85 degrees.

At point C, distance Dis approximately 1.2 inches (30 mm), chamber pressure is approximately 27,200 psi, approximately 80% of maximum chamber pressure M. At point C, the slope of line z is approximately 83 degrees.

At point D, distance Dis approximately 1.4 inches (36 mm), chamber pressure is approximately 27,200 psi, approximately 70% of maximum chamber pressure M. At point D, the slope of line z is approximately 80 degrees.

At point E, distance Dis approximately 2.2 inches (56 mm), chamber pressure is approximately 13,600 psi, approximately 40% of maximum chamber pressure M. At point E, the slope of line z is approximately 60 degrees.

At point F, distance Dis approximately 3.1 inches (79 mm), chamber pressure is approximately 8,500 psi, approximately 25% of maximum chamber pressure M. At point F, the slope of line z is approximately 40 degrees.

In one embodiment, distance Dis positioned such that the chamber pressure at portis between 40 and 90 percent of maximum chamber pressure M. In another embodiment, distance Dis positioned such that the chamber pressure at portis between 40 and 80 percent of maximum chamber pressure M. In yet another embodiment, distance Dis positioned such that the chamber pressure at portis between 40 and 70 percent of maximum chamber pressure M. In another embodiment, distance Dis positioned such that the chamber pressure at portis between 40 and 60 percent of maximum chamber pressure M. In yet another embodiment, distance Dis positioned such that the chamber pressure at portis between 50 and 55 percent of maximum chamber pressure M. In yet another embodiment, distance Dis positioned such that the chamber pressure at portis between 50 and 60 percent of maximum chamber pressure M. In yet another embodiment, distance Dis positioned such that the chamber pressure at portis between 50 and 70 percent of maximum chamber pressure M.

In one embodiment, distance Dis positioned such that the slope of a plot of chamber pressure vs. distance from the breech face at portis between 40 and 85 degrees. In another embodiment, distance Dis positioned such that the slope of a plot of chamber pressure vs. distance from the breech face at portis between 40 and 83 degrees. In yet another embodiment, distance Dis positioned such that the slope of a plot of chamber pressure vs. distance from the breech face at portis between 40 and 80 degrees. In another embodiment, distance Dis positioned such that the slope of a plot of chamber pressure vs. distance from the breech face at portis between 40 and 75 degrees. In yet another embodiment, distance Dis positioned such that the slope of a plot of chamber pressure vs. distance from the breech face at portis between 40 and 70 degrees. In another embodiment, distance Dis positioned such that the slope of a plot of chamber pressure vs. distance from the breech face at portis between 60 and 70 degrees.

While the present disclosure has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that a preferred embodiment has been shown and described and that all changes, equivalents, and modifications that come within the spirit of the claimed invention defined by following claims are desired to be protected.

The language used in the claims and the written description and in the above definitions is to only have its plain and ordinary meaning, except for terms explicitly defined above. Such plain and ordinary meaning is defined here as inclusive of all consistent dictionary definitions from the most recently published (on the filing date of this document) general purpose Merriam-Webster dictionary.