Belted Magnum
The term belted magnum or belted case refers to any cartridge, but generally a rifle cartridge, with a shell casing that has a pronounced "belt" around its base that continues 2–4 mm past the extractor groove. This design originated with the British gunmaker Holland & Holland for the purpose of headspacing certain more powerful cartridges. Non-shouldered (non-"bottlenecked") magnum rifle cartridges especially could be pushed too far into the chamber and thus cause catastrophic failure of the gun when fired with excessive headspace. The addition of the belt to the casing prevented over-insertion. An example of an American adaption of this practice is seen in cartridges like the .458 Winchester Magnum The .458 Winchester Magnum is a belted, straight-taper cased, big five game rifle cartridge. It was introduced commercially in 1956 by Winchester and first chambered in the Winchester Model 70 African rifle. It was designed to compete against t ..., also a shoulderless heavy m ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Rim (firearms)
A rim is an external flange that is machined, cast, molded, stamped, or pressed around the bottom of a firearms cartridge. Thus, rimmed cartridges are sometimes called "flanged" cartridges. Almost all cartridges feature an extractor or headspacing rim, in spite of the fact that some cartridges are known as "rimless cartridges". The rim may serve a number of purposes, including providing a lip for the extractor to engage, and sometimes serving to headspace the cartridge. Types There are various types of firearms rims in use in modern ammunition. The main types are categorized as rimmed, rimless, semi-rimmed, rebated rim, and belted. These describe the size of the rim in relation to the base of the case. Rimmed The rimmed cartridge, sometimes called flanged cartridge, is the oldest of the types and has a rim that is significantly larger in diameter than the base of the cartridge. Rimmed cartridges use the rim to hold the cartridge in the chamber of the firearm, with the rim serv ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Holland & Holland
Holland & Holland is a British gunmaker and clothing retailer based in London, England, which offers handmade sporting rifles and shotguns. The company holds two royal warrants. History Holland & Holland was founded by Harris Holland (1806–1896) in 1835. Harris Holland was born in 1806 in London. Although accounts of his background are somewhat sketchy, it is believed that his father was an organ builder, while Harris had a tobacco wholesale business in London. He was successful, and was often seen at various pigeon shoots at important London clubs, as well as leasing a grouse moor in Yorkshire. Having no children of his own, he took on his nephew Henry Holland as an apprentice in 1861. In 1867 Henry became a partner and in 1876 the name changed to Holland & Holland. Although Henry was a full partner, Harris kept strict control and was the only one who could sign a cheque until he died in 1896. At first, the guns bore the inscription H.Holland, without an address, and ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Headspace (firearms)
In firearms, headspace is the distance measured from a closed chamber's breech face to the chamber feature that limits the insertion depth of a cartridge placed in it. Used as a verb by firearms designers, ''headspacing'' refers to the act of stopping deeper cartridge insertion. The exact part of the cartridge that seats against the limiting chamber feature differs among cartridge and gun designs. Davis, William C., Jr. ''Handloading'' (1981) National Rifle Association pp.67-69 Bottleneck rifle cartridges headspace on their case shoulders; rimmed cartridges headspace on the forward surfaces of their case rims; belted cartridges headspace on the forward surfaces of their case belts; rimless pistol cartridges headspace on their case mouths. When headspace is larger than the cartridge case, there is front-to-back cartridge wiggle room when the breech of the gun is closed. This extra space is called ''head clearance''. Many, including some major manufacturers, confuse head clea ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Catastrophic Failure
A catastrophic failure is a sudden and total failure from which recovery is impossible. Catastrophic failures often lead to cascading systems failure. The term is most commonly used for structural failures, but has often been extended to many other disciplines in which total and irrecoverable loss occurs, such as a head crash occurrence on a hard disk drive. Such failures are investigated using the methods of forensic engineering, which aims to isolate the cause or causes of failure. For example, catastrophic failure can be observed in steam turbine rotor failure, which can occur due to peak stress on the rotor; stress concentration increases up to a point at which it is excessive, leading ultimately to the failure of the disc. In firearms, catastrophic failure usually refers to a rupture or disintegration of the barrel or receiver of the gun when firing it. Some possible causes of this are an out-of-battery gun, an inadequate headspace, the use of incorrect ammunition, the use ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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458 Winchester Magnum
The .458 Winchester Magnum is a belted, straight-taper cased, big five game rifle cartridge. It was introduced commercially in 1956 by Winchester and first chambered in the Winchester Model 70 African rifle. It was designed to compete against the .450 Nitro Express and the .470 Nitro Express cartridges used in big bore British double rifles. The .458 Winchester Magnum remains one of the most popular large game cartridges, and most major ammunition manufacturers offer a selection of .458 ammunition. History The .458 Winchester Magnum was designed for hunting dangerous game animals by emulating the performance of powerful English double rifle cartridges in a bolt-action rifle. The use of a bolt-action rifle offered hunters a cheaper alternative to the big-bore double rifle, and ammunition could be manufactured using available tooling. The .458 Winchester Magnum soon became a success as dangerous game hunters adopted the cartridge. Soon game wardens, wildlife managers, and profes ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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375 H&H Magnum
__NOTOC__ Year 375 ( CCCLXXV) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year after the Consulship of Augustus and Equitius (or, less frequently, year 1128 ''Ab urbe condita''). The denomination 375 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * November 17 – Emperor Valentinian I concludes an enduring peace with the Alamanni in Germany, then marches into Illyricum to repel an invasion of the Quadi and the Sarmatians on the Danube frontier. While negotiating with the Quadi, Valentinian, age 54, becomes so enraged that he dies in a fit of apoplexy at Brigetio (Hungary). Extreme cruelty has marked his 11-year reign, but he has also founded schools and provided physicians to serve the poor of Constantinople. * The Quadi accept an uneasy p ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |