Touchhole
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Touchhole
A touch hole, also called a vent, is a small hole at the rear (breech) portion of the barrel of a muzzleloading gun or cannon. The hole provides external access of an ignition spark into the breech chamber of the barrel (where the combustion of the propellant occurs), either with a slow match (matchlock), a linstock or a flash pan ignited by some type of pyrite- (wheellock) or flint-based gunlock (snaplock, snaphaunce and flintlock), which will initiate the combustion of the main gunpowder charge. Without touch hole, it would be nearly impossible to ignite the powder because the only otherwise access into the barrel is from the front via the muzzle, which is obturated by the projectile. In the later caplock firearms, the ignition sparks are generated by a shock-sensitive percussion cap placed over a conical "nipple", which has a hollow conduit known as the flash channel, that leads into the barrel and serves the same function as the touch hole. In modern breechloading fir ...
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Lock (firearm)
The lock of a firearm is the mechanism used to initiate firing. It is a historical term, in that it generally refers to such mechanisms used in muzzle-loading and early breech-loading firearms. Side-lock refers to the type of construction, in which the individual components of the mechanism are mounted either side of a single plate. The assembly is then mounted to the stock on the side of the firearm. In modern firearm designs, the mechanism to initiate firing is generally constructed within the frame or receiver of the firearm and is referred to as the firing or trigger mechanism. Hand cannon Hand cannon, the earliest of firearms, had arrived in Europe by 1338. These cannons were loaded from the muzzle. The propellent charge is lit through a touch hole. A small priming charge over the touch hole is ignited with a lit piece of slow match or similar. These hand cannons were ungainly: the difficulty being in holding and aiming the weapon while manipulating the slow burni ...
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Gunpowder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate (saltpeter). The sulfur and carbon act as fuels while the saltpeter is an oxidizer. Gunpowder has been widely used as a propellant in firearms, artillery, rocketry, and pyrotechnics, including use as a blasting agent for explosives in quarrying, mining, building pipelines and road building. Gunpowder is classified as a low explosive because of its relatively slow decomposition rate and consequently low brisance. Low explosives deflagrate (i.e., burn at subsonic speeds), whereas high explosives detonate, producing a supersonic shockwave. Ignition of gunpowder packed behind a projectile generates enough pressure to force the shot from the muzzle at high speed, but usually not enough force to rupture the gun barrel. It thus makes a good propellan ...
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Wheellock
A wheellock, wheel-lock or wheel lock is a friction-wheel mechanism which creates a spark that causes a firearm to fire. It was the next major development in firearms technology after the matchlock and the first self-igniting firearm. Its name is from its rotating steel wheel to provide ignition. Developed in Europe around 1500, it was used alongside the matchlock and later the snaplock (1540s), the snaphance (1560s) and the flintlock (c. 1610s). Design The wheellock works by spinning a spring-loaded steel wheel against a piece of pyrite to generate intense sparks, which ignite gunpowder in a pan, which flashes through a small touchhole to ignite the main charge in the firearm's barrel. The pyrite is clamped in vise jaws on a spring-loaded arm (or 'dog'), which rests on the pan cover. When the trigger is pulled, the pan cover is opened, and the wheel is rotated, with the pyrite pressed into contact. A close modern analogy of the wheellock mechanism is the operation of a lighte ...
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Snaplock
A snaplock is a type of lock for firing a gun or is a gun fired by such a lock. A snaplock ignites the (usually muzzle-loading) weapon's propellant by means of sparks produced when a spring-powered cock strikes a flint down on to a piece of hardened steel. The snaplock is therefore similar to the snaphaunce (sometimes classed as an advanced type of snaplock) and the later flintlock (see below). In all snaplocks, the flint is held in a clamp at the end of a bent lever called the cock. When the gun is "cocked", the cock is held back, against the pressure of a spring, by a catch which is part of the trigger mechanism. When the trigger is pulled, the catch is released and the spring moves the cock rapidly forwards. The flint strikes a curved plate of hardened steel, called the "steel". The flint strikes from the steel a shower of white hot steel shavings (sparks) which fall towards the priming powder held in the flash pan. The flash from the pan's ignited primer travels (unless ...
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Breechloading
A breechloader is a firearm in which the user loads the ammunition (cartridge or shell) via the rear (breech) end of its barrel, as opposed to a muzzleloader, which loads ammunition via the front ( muzzle). Modern firearms are generally breech-loading – except for replicas of vintage weapons. Early firearms before the mid-19th century were almost entirely muzzle-loading. Mortars and the Russian GP-25 grenade launcher are the only muzzleloaders remaining in frequent modern usage. However, referring to a weapon specifically as breech loading is mostly limited to single-shot or otherwise non-repeating firearms, such as double-barreled shotguns. Breech-loading provides the advantage of reduced reloading time, because it is far quicker to load the projectile and propellant into the chamber of a gun/cannon than to reach all the way over to the front end to load ammunition and then push them back down a long tube – especially when the projectile fits tightly and the tu ...
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Pipe (fluid Conveyance)
A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipe is far stiffer per unit weight than solid members. In common usage the words ''pipe'' and ''tube'' are usually interchangeable, but in industry and engineering, the terms are uniquely defined. Depending on the applicable standard to which it is manufactured, pipe is generally specified by a nominal diameter with a constant outside diameter (OD) and a schedule that defines the thickness. Tube is most often specified by the OD and wall thickness, but may be specified by any two of OD, inside diameter (ID), and wall thickness. Pipe is generally manufactured to one of several international and national industrial standards. While similar standards exist for specific industry applicati ...
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Percussion Cap
The percussion cap or percussion primer, introduced in the early 1820s, is a type of single-use percussion ignition device for muzzle loader firearm locks enabling them to fire reliably in any weather condition. This crucial invention gave rise to the cap lock mechanism or percussion lock system using percussion caps struck by the hammer to set off the gunpowder charge in percussion guns including percussion rifles and cap and ball firearms. Any firearm using a caplock mechanism is a percussion gun. Any long gun with a cap-lock mechanism and rifled barrel is a percussion rifle. Cap and ball describes cap-lock firearms discharging a single bore-diameter spherical bullet with each shot. 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 1850 to the early 20th ...
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Shock Sensitivity
Shock sensitivity is a comparative measure of the sensitivity to sudden compression (by impact or blast) of an explosive chemical compound. Determination of the shock sensitivity of a material intended for practical use is one important aspect of safety testing of explosives. A variety of tests and indices are in use, of which one of the more common is the Rotter Impact Test with results expressed as FoI ( Figure of Insensitivity.) At least four other impact tests are in common use, while various "gap tests" are used to measure sensitivity to blast shock. Sensitivities vary widely A few materials such as nitrogen triiodide cannot be touched at all without detonating, and so are of purely academic interest. Some other compounds with a high sensitivity to shock, such as nitroglycerin and acetone peroxide, may detonate from a firm jolt and so cannot be legally transported in pure form. Acetone peroxide is often used by amateurs and terrorists as a means to detonate other explosives ...
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Caplock
The percussion cap or percussion primer, introduced in the early 1820s, is a type of single-use percussion ignition device for muzzle loader firearm locks enabling them to fire reliably in any weather condition. This crucial invention gave rise to the cap lock mechanism or percussion lock system using percussion caps struck by the hammer to set off the gunpowder charge in percussion guns including percussion rifles and cap and ball firearms. Any firearm using a caplock mechanism is a percussion gun. Any long gun with a cap-lock mechanism and rifled barrel is a percussion rifle. Cap and ball describes cap-lock firearms discharging a single bore-diameter spherical bullet with each shot. 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 explosive material#Primary explosive, shock-sensitive explosive material such as mercury(II) fulminate, mercuric fulminate (discovered in 1800; it was the only prac ...
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Projectile
A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found in warfare and sports (for example, a thrown baseball, kicked football, fired bullet, shot arrow, stone released from catapult). In ballistics mathematical equations of motion are used to analyze projectile trajectories through launch, flight, and impact. Motive force Blowguns and pneumatic rifles use compressed gases, while most other guns and cannons utilize expanding gases liberated by sudden chemical reactions by propellants like smokeless powder. Light-gas guns use a combination of these mechanisms. Railguns utilize electromagnetic fields to provide a constant acceleration along the entire length of the device, greatly increasing the muzzle velocity. Some projectiles provide propulsion during flight by means of a rocket engine ...
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Obturate
In the field of firearms and airguns, obturation denotes necessary barrel blockage or fit by a deformed soft projectile (obturation in general is closing up an opening). A bullet or pellet, made of soft material and often with a concave base, will flare under the heat and pressure of firing, filling the bore and engaging the barrel's rifling. The mechanism by which an undersized soft-metal projectile enlarges to fill the barrel is, for hollow-base bullets, expansion from gas pressure within the base cavity and, for solid-base bullets, "upsetting"—the combined shortening and thickening that occurs when a malleable metal object is struck forcibly at one end. For shotgun shells which have multiple pellets much smaller than the barrel bore, obturation is achieved by placing a plastic wad or biodegradable card of the same diameter as the barrel between the propellant powder and the pellets. More importantly, "obturation" refers to the action of a soft metallic cartridge case bein ...
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Muzzle (firearms)
A gun barrel is a crucial part of gun-type weapons such as small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure gas(es) is used to propel a projectile out of the front end ( muzzle) at a high velocity. The hollow interior of the barrel is called the bore, and the diameter of the bore is called its caliber, usually measured in inches or millimetres. The first firearms were made at a time when metallurgy was not advanced enough to cast tubes capable of withstanding the explosive forces of early cannons, so the pipe (often built from staves of metal) needed to be braced periodically along its length for structural reinforcement, producing an appearance somewhat reminiscent of storage barrels being stacked together, hence the English name.''A History of Warfare'' - Keegan, John, Vintage 1993. History Gun barrels are usually metal. However, the earl ...
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