Percussion cap
The percussion cap, percussion primer, or caplock, introduced in the early 1820s, is a type of single-use percussion ignition device for
Description
The percussion cap is a small cylinder of copper or brass with one closed end. Inside the closed end is a small amount of a shock-sensitive explosive material such as mercuric fulminate (discovered in 1800; it was the only practical detonator used from about the mid-19th century to the early 20th century[2]).
The caplock mechanism consists of a hammer and a nipple (sometimes referred to as a cone). The nipple contains a hollow conduit which goes into the rearmost part of the gun barrel, and the percussion cap is placed over the nipple hole. Pulling the trigger releases the hammer, which strikes the percussion cap against the nipple (which serves as an anvil), crushes it and detonates the mercury fulminate inside, which releases sparks that travel through the hollow nipple into the barrel and ignite the main powder charge.
Percussion caps have been made in small sizes for pistols and larger sizes for rifles and muskets.[1]
Origins
Earlier firearms used flintlock mechanisms causing a piece of flint to strike a steel frizzen producing sparks to ignite a pan of priming powder and thereby fire the gun's main powder charge. The flintlock mechanism replaced older ignition systems such as the matchlock and wheellock, but all were prone to misfire in wet weather.[citation needed]
The discovery of
The first purpose-built caplock guns were
The caplock offered many improvements over the flintlock. The caplock was easier and quicker to load, more resilient to weather conditions, and far more reliable than the flintlock. Many of the older flintlock weapons were later converted to the caplock, so that they could take advantage of these features.[1]
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Japanese samurai's matchlock converted to percussion lock
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A pair of caplock twister pistols
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Inverted percussion pistol, 9.5 mm; made by gunsmith Correvon, Morges, 1854
Parallel developments
Joshua Shaw is sometimes credited (primarily by himself) with the development of the first metallic percussion cap in 1814, a reusable one made of iron, then a disposable pewter one in 1815 and finally a copper one in 1816. There is no independent proof of this since Shaw was advised he could not patent it due to Alexander Forsyth's patent for using fulminates to ignite guns being in force between 1807 and 1821. Shaw says he only shared the development of his innovation with a few associates (gunmakers and others) who were sworn to secrecy and never provided affidavits at a later date. Shaw's claim to have been the inventor remains clouded in controversy as he did not patent the idea until 1822, having moved to America in 1817. According to Lewis Winant, the US government's decision to award Shaw $25,000 as compensation for his invention being used by the Army was a mistake. Congress believed Shaw's patent was the earliest in the world and awarded him a large sum of money based on this belief. The investigators had overlooked two French patents and the earlier use of the idea in Britain.
The earliest known patent anywhere in the world which specifically mentions a percussion cap and nipple was granted in France on 29 July 1818 to François Prélat, four years before Shaw's patent. Prelat made a habit of copying English patents and inventions and the mode of operation he describes is flawed.[10] Secondly a French patent of a percussion cap and nipple had been granted in 1820 to Deboubert. However predating both of these French claims, the most likely inventor of the percussion cap, according to historian Sidney James Gooding, was Joseph Egg (nephew of Durs Egg), around 1817, .[11]
There were other earlier claims. Col. Peter Hawker in 1830 simultaneously claimed and denied being the inventor. "I do not wish to say I was the inventor of it - very probably not" but then immediately recounts that he came up with the idea of simplifying a Manton patch-lock, which could be troublesome, by designing a cap and nipple arrangement around 1816 when the patch lock was patented. He says he then presented a drawing to a reluctant Joseph Manton to make a few copper cap guns which were then sold.[12] Hawker, seems to give Joseph Manton more of the glory eight years later in the 1838 edition of his 'Instructions to young Sportsmen', by stating categorically that "copper tubes and primers were decidedly invented by Joe Manton". By the 1850s Hawker was again claiming the invention for himself in his press advertisements.[13]
Despite many years of research by Winant, Gooding and De Witt Bailey, the jury is still out as the competing claims are based on personal accounts and have little or no independently verifiable evidence.
While the metal percussion cap was the most popular and widely used type of primer, their small size made them difficult to handle under the stress of combat or while riding a horse. Accordingly, several manufacturers developed alternative, "auto-priming" systems. The "Maynard tape primer", for example, used a roll of paper "caps" much like today's toy cap gun. The Maynard tape primer was fitted to some firearms used in the mid-nineteenth century and a few saw brief use in the American Civil War. Other disc or pellet-type primers held a supply of tiny fulminate detonator discs in a small magazine. Cocking the hammer automatically advanced a disc into position. However, these automatic feed systems were difficult to make with the manufacturing systems in the early and mid-nineteenth century and generated more problems than they solved. They were quickly shelved in favor of a single percussion cap that, while unwieldy in some conditions, could be carried in sufficient quantities to make up for occasionally dropping one, while a jammed tape primer system would instead reduce the rifle to an awkward club.[1]
Military firearms
This invention was gradually improved, and came to be used, first in a steel cap and then in a copper cap, by various gunmakers and private individuals before coming into general military use nearly thirty years later. The alteration of the military flintlock to the percussion musket was easily accomplished by replacing the powder pan and steel frizzen with a nipple and by replacing the cock or hammer that held the flint by a smaller hammer formed with a hollow made to fit around the nipple when released by the trigger. On the nipple was placed the copper cap containing Shaw's detonating composition of three parts of chlorate of potash, two of fulminate of mercury and one of powdered glass. The hollow in the hammer contained the fragments of the cap if it fragmented, reducing the risk of injury to the firer's eyes. From the 1820s onwards, the armies of Britain, France, Russia, and America began converting their muskets to the new percussion system. Caplocks were generally applied to the British military musket (the
The Austrians instead used a variant of Manton's tube lock in their
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Springfield and Enfield caplocks
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Detail of the firing mechanism on an instruction cutaway model of a French navy percussion pistol, model 1837
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Caplockhorse pistol, Swiss Ordnance 1817/42
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Loading sequence for percussion revolvers
Later firearms evolution
The percussion cap brought about the invention of the modern
Caplock revolvers such as the
In the 1840s and 1850s, the percussion cap was first integrated into a metallic cartridge, where the bullet is held in by the casing, the casing is filled with gunpowder, and a
Today, reproduction percussion firearms are popular for recreational shooters and percussion caps are still available (though some modern muzzleloaders use
Other uses
Caps are used in
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Alternative design of USSR booby trap firing device – pull fuze: normally connected to tripwire. Percussion cap is clearly labelled.
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USSR boobytrap firing device – pressure fuze: victim steps on loose floorboard with fuze concealed underneath.
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Cross-sectional view of a Japanese Type 99 grenade showing percussion primer
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Cross-sectional view of the fuze fitted to a German S-mine. Percussion cap is clearly labelled.
See also
- Arquebus
- Cap gun
- Internal ballistics
- Minié ball
- Nipple wrench
- Primer (firearms)
- Tubes and primers for ammunition
Citations
- ^ ]
- ISSN 0187-893X.
- ^ Howard, Edward (1800) "On a New Fulminating Mercury," Philosophical Transactions of the Royal Society of London 90 (1): 204–238.
- ^ Edward Charles Howard at National Portrait Gallery
- ^ Percussion lock
- ^ Samuel Parkes, The chemical catechism : with notes, illustrations, and experiments, New York : Collins and Co., 1818, page 494 (page 494 online, see "LVI. A New Kind of Gunpowder.")
- ]
- ^ "Joshua Shaw". Archived from the original on 18 February 2012. Retrieved 5 November 2018.
- ISBN 978-1-78274-266-1.
- ^ "Early Percussion Firearms". Spring Books. 25 October 2015.
- ]
- ^ Hawker, Peter (1830). "Instructions to Young Sportsmen 6th edition (1830)". Retrieved 3 July 2021.
- ^ "Hawker Ad - Inventor of the Copper Cap". Hampshire Chronicle. 30 November 1850.
- ^ "Met Museum". Met Museum. Retrieved 5 November 2018.
- ^ "Kammerbusche". Militarygunsofeurope.eu. Archived from the original on 25 October 2018. Retrieved 5 November 2018.
- ^ Dreyse needle gun
- ^ "Loading and firing a Snider Enfield". Militaryheritage.com. Retrieved 5 November 2018.
- ^ "Britain's big 577". Retrieved 5 November 2018 – via The Free Library.
- ^ "Colt revolver in the Old West". Archived from the original on 22 April 2012. Retrieved 5 November 2018.
Bibliography
- Winant, L. (1956). Early percussion firearms. Bonanza Books