Gas-operated reloading
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Gas-operation is a system of operation used to provide energy to operate
History
The first mention of using a gas piston in a single-shot breech-loading rifle comes from 1856, by the German Edward Lindner who patented his invention in the United States and Britain.[1] In 1866, Englishman William Curtis filed the first patent on a gas-operated repeating rifle but subsequently failed to develop that idea further.[2] Between 1883 and 1885, Hiram Maxim filed several patents on blowback-, recoil-, and gas-operation. In 1885, one year after Maxim's first gas-operated patent, a British inventor called Richard Paulson, who a year before had patented a straight blowback-operated rifle and pistol, again, one year after Maxim’s first blowback patent, patented a gas piston-operated rifle and pistol which he claimed could be used with sliding, rotating or falling bolts. He would also patent a gas-operated revolver in 1886. Paulson did construct models of his rifle and tried them in France shortly after filing his patent.[3] Furthermore, according to
A. W. F. Taylerson, a firearms historian, his patented revolver was probably workable.
Piston systems
Most current gas systems employ some type of piston. The face of the piston is acted upon by combustion gas from a port in the barrel or a trap at the muzzle. Early guns, such as Browning's "flapper" prototype, the
Gas trap
A gas trap system involves "trapping" combustion gas as it leaves the muzzle. This gas impinges on a surface that converts the energy to motion that, in turn, cycles the action of the firearm. As the resulting motion is forward toward the muzzle of the gun, some sort of mechanical system is needed to translate this into the rearward motion needed to operate the bolt. This adds to the complexity of the mechanism and its weight, and the placement of the trap generally results in a longer weapon and allows dirt to easily enter the mechanism. Despite these disadvantages, they use relatively low pressure gas and do not require a hole in the barrel, which made them attractive in early designs. The system is no longer used in modern weapons.
The American and German governments both had requirements that their guns operated without a hole being drilled in the barrel. Both governments would first adopt weapons and later abandon the concept. Most earlier US M1 Garand rifles were retrofitted with long-stroke gas pistons, making the surviving gas trap rifles valuable in the collector's market.
In the 1980s Soviet designer Alexander Adov from TsKIB SOO modified the concept with a tube diverting gas from the muzzle to a standard long stroke system (see below) in order to diminish influence of the gas engine on barrel and increase accuracy, but his sniper rifle wasn't adopted due to the dissolution of the Soviet Union.[11]
Long-stroke
With a long-stroke system, the piston is mechanically fixed to the bolt group and moves through the entire operating cycle. This system is used in weapons such as the
Short-stroke
With a short-stroke or tappet system, the piston moves separately from the bolt group. It may directly push
Short-stroke fixed
It is a cross between a short-stroke gas piston and a M1 Garand type long-stroke gas piston system. It is similar to a regular short-stroke piston in operation because it too uses an open gas piston that has an impingement cavity at its head, that rests on a gas block on the barrel. However just like the long-stroke gas piston system used on the M1 Garand the piston assembly is integrated with the operating rod and moves with the bolt group.
The caveat of this system is that it has heavier moving mass than modern long-stroke gas piston systems used on rifles like the AK-47, Tavor, FN FNC, etc. Hence firearms using this system do have higher felt recoil than their equivalent modern long-stroke gas piston counterparts.
Gas-delayed blowback
The
pistols.Floating chamber
To avoid consuming a lot of relatively expensive rounds, many armies, including the United States Army,
Direct impingement
The
Other uses of gas in firearms
Several other uses have been found for exhaust gases other than to aid cycling:
- Muzzle booster
- The French Chauchat, German MG 34 and MG 42 machine guns, the British Vickers machine gun, and some other recoil operated firearms use a gas trap style mechanism to provide additional energy to "boost" the energy provided by recoil. This "boost" provides higher rates of fire and/or more reliable operation. It is alternately called a "gas assist", and may also be found in some types of blank-firing adapters.
- Gas ejection
- Patented by August Schüler, the Reform pistol featured a vertical row of barrels that advanced upwards with each shot exposing the fired chamber. As the lower barrel fired, a gas hole between the barrels pressurized the empty barrel enough to eject the case rearward. An extended spur on the hammer prevented the spent case from hitting the firer in the face. The final case required manual extraction.
See also
- Delayed blowback
- Recoil operation
- Blowback operation
- Blow forward
References
- ^ Woodcroft, Bennet (1859). "Abridgments of the Specifications Relating to Fire-arms and Other Weapons, Ammunition, and Accoutrements: A.D. 1588-1858]-Pt. II. A.D. 1858-1866". Great Britain Patent Office.
- ^ "The Curtis Rifle – the First Repeating Bullpup". August 10, 2018.
- ^ "Report of the Committee on Awards of the World's Columbian Commission: Special Reports Upon Special Subjects Or Groups, Volume 2". 1901.
- ^ Taylerson, A. W. F. (1971). "The Revolver, 1889-1914".
- ^ "Magazine-gun".
- ^ "Pitcher 1890 Rifle 30".
- ^ "Automatic Weapons:French Forerunners".
- ISBN 9781783469741.
- ISBN 9781472836151.
- ^ U.S. patent 1,907,163
- ^ "Тульский "Карабинер". Винтовка ТКБ-0145С | Оружейный журнал "КАЛАШНИКОВ"". June 19, 2018.
- ^ U.S. patent 2,090,656 Page 8, column 2, lines 67–70, Pg 9, column 1, lines 22–39
- ^ Charles E. Petty, "Delightful diversion: testing Kimber's new rimfire was a tough job, but someone had to do it", Guns Magazine, March 2004. Contains some discussion about the floating chamber device.
- ISBN 0-9625943-4-2.
- ^ Smith, W.H.B.; Ezell, E. C. (1983), Small Arms of the World, 12th Edition, Stackpole Company, Harrisburg PA
- ^ Major Thomas P. Ehrhart Increasing Small Arms Lethality in Afghanistan: Taking Back the Infantry Half-Kilometer. US Army. 2009