|
Obturation
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 be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rifled Breech Loader
A rifled breech loader (RBL) is an artillery piece which, unlike the smoothbore cannon and rifled muzzle loader (RML) which preceded it, has rifling in the barrel and is loaded from the breech at the rear of the gun. The spin imparted by the gun's rifling gives projectiles directional stability and increased range. Loading from the rear of the gun leaves the crew less exposed to enemy fire, allows smaller gun emplacements or turrets, and allows a faster rate of fire. Overview The major problem to be solved with breechloading artillery was obturation: the sealing of the breech after firing to ensure that none of the gases generated by the burning of the propellant (initially gunpowder) escaped rearwards through the breech. This was both a safety issue and one of gun performance – all the propellant gas was needed to accelerate the projectile along the barrel. The second problem was speed of operation – how to close the breech before firing and open it after firing as qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossary Of Firearms Terminology
The following are terms related to firearms and ammunition topics. A *Accurize, accurizing: The process of altering a stock firearm to improve its accuracy. * Action: The physical mechanism that manipulates cartridges and/or seals the breech. The term refers to the method in which cartridges are loaded, locked, and extracted from the mechanism. Actions are generally categorized by the type of mechanism used. A firearm action is technically not present on muzzleloaders as all loading is done by hand. The mechanism that fires a muzzleloader is called the lock. *Adjustable sight: Iron sights that allow the user to change the markings, intended for firing at multiple possible ranges. *Ammunition or ammo: Gunpowder and artillery. Since the design of the cartridge, the meaning has been transferred to the assembly of a projectile and its propellant in a single package. * Assault rifle: A service rifle capable of semi- or full automatic fire, that fires intermediate cartridges. *Assaul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minié Ball
The Minié ball or Minie ball, is a type of hollow-based bullet designed by Claude-Étienne Minié, inventor of the French Minié rifle, for muzzle-loading rifled muskets. It was invented in 1847 and came to prominence in the Crimean War and the American Civil War, where it was found to inflict significantly more serious wounds than earlier round musket balls. Both the American Springfield Model 1861 and the British Pattern 1853 Enfield rifled muskets, the most common weapons used during the American Civil War, used the Minié ball. Rifling, the addition of spiral grooves inside a gun barrel, imparts a stabilizing spin to a projectile for better external ballistics, greatly increasing the effective range and accuracy of the gun. Before the introduction of the Minié ball, balls had to be rammed down the barrel, sometimes with a mallet, because gunpowder residue would foul a rifled bore after a relatively small number of shots, requiring frequent cleaning of the gun. McPher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Ballistics
Internal ballistics (also interior ballistics), a subfield of ballistics, is the study of the propulsion of a projectile. In guns, internal ballistics covers the time from the propellant's ignition until the projectile exits the gun barrel. The study of internal ballistics is important to designers and users of firearms of all types, from small-bore rifles and pistols, to high-tech artillery. For rocket-propelled projectiles, internal ballistics covers the period during which a rocket motor is providing thrust. Parts and equations Hatcher breaks the duration of interior ballistics into three parts: *Lock time, the time from sear release until the primer is struck *Ignition time, the time from when the primer is struck until the projectile starts to move *Barrel time, the time from when the projectile starts to move until it exits the barrel. There are many processes that are significant. The source of energy is the burning propellant. It generates hot gases that raise the chamb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hollow-base Bullet
A hollow-base bullet is a firearm bullet with a pit or hollow in its base which expands upon being fired, forcing the base to engage with the barrel grooves and obturating the bore more as the bullet travels through the barrel. Hollowing the base makes the bullet more front-heavy, which improves aerodynamic stability and accuracy. History Two men have been credited with the invention of the hollow-base bullet: Captain Claude-Étienne Minié of the French Army and William Greener. The initial reason for developing a hollow-base bullet was to improve usability and performance of muzzle-loading rifles using black powder propellant. See also * Hollow-point bullet * Minié ball The Minié ball or Minie ball, is a type of hollow-based bullet designed by Claude-Étienne Minié, inventor of the French Minié rifle, for muzzle-loading rifled muskets. It was invented in 1847 and came to prominence in the Crimean War an ... * Tamisier * Nessler ball References * Notes {{ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shotgun Shell
A shotgun shell, shotshell or simply shell is a type of rim (firearms), rimmed, cylindrical (straight-walled) cartridge (firearms), cartridges used specifically in shotguns, and is typically loaded with numerous small, pellets (petrology), pellet-like spherical sub-projectiles called shot (pellet), shot, fired through a smoothbore gun barrel, barrel with a choke (firearms), tapered constriction at the muzzle to regulate the extent of shot grouping#Uses of the term, scattering. A shell can sometimes also contain only a single large solid projectile known as a shotgun slug, slug, fired usually through a rifling, rifled slug barrel. The cartridge (firearms)#Case, hull usually consists of a paper cartridge#Paper shotshells, paper or polymer-cased ammunition, plastic tube often covered at the base by a metallic head cover which retains a primer (firearms), primer, and the shot charge is typically contained by a wadding/sabot (firearms), sabot inside the case. The caliber of the shots ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firearms
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions). The first firearms originated in 10th-century China, when bamboo tubes containing gunpowder and pellet projectiles were mounted on spears to make the portable fire lance, operable by a single person, which was later used effectively as a shock weapon in the Siege of De'an in 1132. In the 13th century, fire lance barrels were replaced with metal tubes and transformed into the metal-barreled hand cannon. The technology gradually spread throughout Eurasia during the 14th century. Older firearms typically used black powder as a propellant, but modern firearms use smokeless powder or other propellants. Most modern firearms (with the notable exception of smoothbore shotguns) have rifled barrels to impart spin to the projectile for improved flight stability. Modern firearms can be described by their caliber ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wadcutter
A wadcutter is a special-purpose flat-fronted bullet specifically designed for shooting paper targets, usually at close range and at subsonic velocities typically under approximately 900 ft/s (274 m/s). Wadcutters have also found favor for use in self-defense guns, such as .38 caliber snubnosed revolvers, where, due to short barrel lengths, maximum bullet velocities are usually low, typically under 900 ft/s (274 m/s), and improved lethality is desired. Wadcutters are often used in handgun and airgun competitions. Bullet profile A wadcutter has a flat or nearly flat front that is typically as wide as the caliber size or only slightly smaller in diameter than caliber size. For target shooting, a wadcutter cuts a very clean hole through the paper target, making it easier to score and ideally reducing errors in scoring the target in the favor of the shooter. Because the flat nosed bullet is not well suited for feeding out of a magazine, wadcutters are normally use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammunition
Ammunition (informally ammo) is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons (e.g., bombs, missiles, grenades, land mines) and the component parts of other weapons that create the effect on a target (e.g., bullets and warheads). The purpose of ammunition is to project a force against a selected target to have an effect (usually, but not always, lethal). An example of ammunition is the firearm cartridge, which includes all components required to deliver the weapon effect in a single package. Until the 20th century, black powder was the most common propellant used but has now been replaced in nearly all cases by modern compounds. Ammunition comes in a great range of sizes and types and is often designed to work only in specific weapons systems. However, there are internationally recognized standards for certain ammunition types (e.g., 5.56×45mm NATO) that enable their use across different wea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Check
A gas check is a gasket type component of firearms ammunition. Gas checks are used when non- jacketed bullets are used in high pressure cartridges. The use of a gas check inhibits the buildup of lead in the barrel and improves accuracy. Construction Gas checks are most commonly found in the form of a thin cup or disc made of a ductile metal. Copper, zinc, aluminum, and alloys such as brass have been used. A bullet designed to accept a gas check has a rebated base shank which permits attachment of the check without altering the maximum diameter of the bullet. The shallow cup-shaped check is mechanically attached to the reduced shank of the bullet by swaging. Purpose High pressures, such as those commonly encountered in maximum loadings of magnum revolver cartridges or rifle cartridges, often result in significant problems when coupled with cast or swaged lead bullets. It was long thought that the high temperatures melted the base of the bullet, but this is no longer thought ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Driving Band
Russian 122 mm shrapnel shell, which has been fired, showing rifling marks on the copper driving band around its base and the steel bourrelet nearer the front A driving band or rotating band is a band of soft metal near the base of an artillery shell, often made of gilding metal, copper, or lead. When the shell is fired, the pressure of the propellant swages the metal into the rifling of the barrel and forms a seal; this seal prevents the gases from blowing past the shell, and engages the barrel's rifling to spin-stabilize the shell. Purpose The rotating band has three essential functions: * Center the rear end of the projectile in the gun barrel. * Seal the bore to prevent burning powder gas from moving through the rifling grooves past the projectile. * Engage with the rifling of the barrel to spin the projectile and stabilize its flight. Characteristics The shell is stabilized for yaw in the barrel by a smaller bourrelet band near the front of the projectile. This band ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quick-firing Gun
A quick-firing or rapid-firing gun is an artillery piece, typically a gun or howitzer, which has several characteristics which taken together mean the weapon can fire at a fast rate. Quick-firing was introduced worldwide in the 1880s and 1890s and had a marked impact on war both on land and at sea. Characteristics The characteristics of a quick-firing artillery piece are: *A breech-loading weapon with a breech mechanism that allows rapid reloading *Single-part cased ammunition, i.e. a cartridge containing both shell and propellant * Recoil buffers to limit recoil, so the barrel can quickly return to the same position after firing *The use of smokeless powder – nitrocellulose, nitroglycerine, or cordite – which create far less smoke than gunpowder, meaning that gun crews could still see their target These innovations, taken together, meant that the quick-firer could fire aimed shells much more rapidly than an older weapon. For instance, an Elswick Ordnance Company 4 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
