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Bolt Thrust
Bolt thrust or breech pressure is a term used in internal ballistics and firearms (whether small arms or artillery) that describes the amount of rearward force exerted by the propellant gases on the Bolt (firearms), bolt or Breechblock, breech of a firearm action or Breech-loading weapon, breech when a projectile is fired. The applied force has both Euclidean vector#Length, magnitude and Direction (geometry, geography), direction, making it a Vector (geometric), vector quantity. Bolt thrust is an important factor in weapons design. The greater the bolt thrust, the stronger the locking mechanism has to be to withstand it. Assuming equal engineering solutions and material, adding strength to a locking mechanism causes an increase in weight and size of locking mechanism components. Bolt thrust is not a measure to determine the amount of recoil or free recoil. Calculating bolt thrust With a basic calculation the bolt thrust produced by a particular firearms cartridge can be calculated ... [...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 artillery. For rocket-propelled projectiles, internal ballistics covers the period during which a rocket motor is providing thrust. General concepts Interior ballistics can be considered in three time periods: *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. The burning firearm propellant produces energy in the form of hot gases that raise the chamber pressure which applies a force on the base of the projectile, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NATO EPVAT Testing
NATO EPVAT testing is one of the three recognized classes of procedures used in the world to control the safety and quality of firearms ammunition. Beside this, there are also the ''Commission internationale permanente pour l'épreuve des armes à feu portatives'' (C.I.P.) class of procedures and the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) class of procedures. EPVAT Testing is described in unclassified documents by NATO, more precisely by the AC/225 Army Armaments Group (NAAG). It was accepted as NATO Standardization Agreement STANAG 4823 and Allied Engineering Publication 97 (AEP-97) in November 2020. EPVAT is an abbreviation for "Electronic Pressure, Velocity and Action Time" (French "Pression électronique, vitesse et durée d'action"). Action Time here means the (short amount of) time required between the ignition of the primer and the projectile leaving the barrel. This is a comprehensive procedure for testing ammunition using state-of-the-art instrum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
357 SIG
The .357 SIG (designated as the 357 Sig by the SAAMI and 357 SIG by the C.I.P. or 9×22 mm in official metric notation) is a bottlenecked rimless centerfire handgun cartridge developed by the Swiss-German firearms manufacturer SIG Sauer, in cooperation with ammunition manufacturer Federal Premium. The cartridge is used by a number of law enforcement agencies.''The Gun Digest Book of Sig-Sauer: a complete look at Sig-Sauer pistols.'' Massad Ayoob. 2004. pp. 51–53. History The .357 SIG is based on a necked-down .40 Smith & Wesson case, forgoing the large pistol primer utilized by the 10mm Auto in favor of the small pistol primer used in many common self-defense rounds, such as .40 S&W, .38 Special, 9 mm and other similarly-sized cartridges. Excluding specialized wildcat cartridges used in competition shooting — e.g., the 9×25mm Dillon, which necked a 10mm Auto case down to a 9 mm bullet — the .357 SIG was the first modern bottlenecked handgun cartridge to become ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
357 Magnum
The .357 Smith & Wesson Magnum, .357 S&W Magnum, .357 Magnum, or 9×33mmR (as it is known in unofficial metric designation) is a smokeless powder cartridge with a bullet diameter. It was created by Elmer Keith, Phillip B. Sharpe, and Douglas B. Wesson of firearm manufacturers Smith & Wesson and Winchester. The .357 Magnum cartridge is notable for its highly effective terminal ballistics. The .357 Magnum cartridge is based upon Smith & Wesson's earlier .38 Special cartridge. It was introduced in 1935, and its use has since become widespread. Design The .357 Magnum was collaboratively developed over a period in the early to mid-1930s by a group of individuals as a direct response to Colt's .38 Super Automatic. At the time, the .38 Super was the only American pistol cartridge capable of defeating automobile cover and the early ballistic vests that were just beginning to emerge in the Interwar period. Tests at the time revealed that those vests defeated any handgun bullet trav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HK 4
The HK4 is a pocket pistol, first introduced by Heckler & Koch in either 1964 or 1967. It was distinctive for allowing shooters to swap barrels chambered for different cartridges without tools and for having a durable but light hard-anodized aluminum-alloy frame. Design The HK4 is largely a refined Mauser HSc The Mauser HSc is a 7.65mm pistol introduced in Nazi Germany during World War II, and manufactured until 1977. The designation HSc stood for ''Hahn Selbstspanner'' ("self-cocking hammer") ''Pistole'', third and final design ''"C"''. Production wa ... self-loading pistol. Heckler & Koch were familiar with the HSc design as many of the Heckler & Koch company founders were employees of the Mauser-Werke Oberndorf A.G. company pre- and post-WW2. Similar to the HSc, the HK4 utilizes a straight blowback action, with a double-action trigger and a slide-mounted safety. Additionally, the pistol has a internal safety mechanism that will keep the firing pin misaligned from the hammer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
22 Long Rifle
The .22 long rifle, also known as the .22 LR or 5.7×15mmR, is a long-established variety of .22 caliber rimfire ammunition originating from the United States. It is used in a wide range of firearms including rifles, pistols, revolvers, and submachine guns. In terms of units sold, it is by far the most common ammunition that is manufactured and sold in the world. Common uses include hunting and shooting sports. Ammunition produced in .22 long rifle is effective at short ranges, has little recoil, and is inexpensive to purchase. These qualities make it ideal for plinking and marksmanship training. History American cartridge manufacturer J. Stevens Arms & Tool Company introduced the .22 long rifle cartridge in 1887.The round owes its origin to the .22 BB Cap of 1845 and the .22 Short of 1857. It combined the case of the .22 long of 1871 with a bullet, giving it a longer overall length, a higher muzzle velocity and superior performance as a hunting and target round, render ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilogram-force
The kilogram-force (kgf or kgF), or kilopond (kp, from ), is a non-standard Gravitational metric system, gravitational metric unit of force. It is not accepted for use with the International System of Units (SI) and is deprecated for most uses. The kilogram-force is equal to the magnitude of the force exerted on one kilogram of mass in a gravitational field (standard gravity, a conventional value approximating the average magnitude of gravity on Earth). That is, it is the weight of a kilogram under standard gravity. One kilogram-force is defined as .NIST]''Guide for the Use of the International System of Units (SI)''Special Publication 811, (1995) page 51 Similarly, a gram-force is , and a milligram-force is . History The gram-force and kilogram-force were never well-defined units until the CGPM adopted a ''standard acceleration of gravity'' of 9.80665 m/s2 for this purpose in 1901, though they had been used in low-precision measurements of force before that time. Even then, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bar (unit)
The bar is a metric unit of pressure defined as 100,000 Pa (100 kPa), though not part of the International System of Units (SI). A pressure of 1 bar is slightly less than the current average atmospheric pressure on Earth at sea level (approximately 1.013 bar). By the barometric formula, 1 bar is roughly the atmospheric pressure on Earth at an altitude of 111 metres at 15 °C. The bar and the millibar were introduced by the Norwegian meteorologist Vilhelm Bjerknes, who was a founder of the modern practice of weather forecasting, with the bar defined as one megadyne per square centimetre. The SI brochure, despite previously mentioning the bar, now omits any mention of it.. The bar has been legally recognised in countries of the European Union since 2004. British Standard BS 350:2004 ''Conversion Factors for Units''. The US National Institute of Standards and Technology (NIST) deprecates its use except for "limited use in meteorology" and lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooking Off
Cooking off (or thermally induced firing) is unfired weapon ammunition explosion, exploding prematurely due to heat in the surrounding environment. The term is used both for detonation of ammunition not loaded into a weapon, and unintended firing of a loaded weapon due to heating. A fast cook-off is a cook-off caused by fire. A slow cook-off is caused by a sustained thermal event less intense than fire. A cooked-off round may cause a sympathetic detonation of adjacent rounds. Insensitive munitions are designed to be less vulnerable to accidental firing induced by external heat. Artillery Inherent design flaws in early 17th century Sweden, Swedish leather cannons led to the gun barrel, gun tube overheating which prematurely ignited the gunpowder, injuring the loader. Muzzle-loading cannon on merchant and naval vessels of the Age of Sail would fire if the vessels caught fire while the guns were loaded. Examples include the merchantman and . After the cooking off of artillery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chamber (firearms)
The chamber of a firearm is the cavity at the back end of a breechloading weapon's barrel or cylinder, where the ammunition is inserted before being fired. The rear opening of the chamber is the breech, and is sealed by the breechblock or the bolt. Function The act of ''chambering'' a cartridge means the insertion of a round into the chamber, either manually or through the action of the weapon, e.g., pump-action, lever-action, bolt action, or autoloading operation generally in anticipation of firing the weapon, without need to "load" the weapon upon decision to use it (reducing the number of ''actions'' needed to discharge). Automatic and single-shot pistols (such as Derringers), rifles, and shotguns generally have a single chamber integral to their barrels, but revolvers have multiple chambers in their cylinder, and no chamber in their barrel. Thus, pistols, rifles, and shotguns can usually still be fired with the magazine removed as long as a cartridge is inser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
