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Smokeless powder is the name given to a number of propellants used in firearms and artillery that produce negligible smoke when fired, unlike the black powder they replaced. The term is unique to the United States and is generally not used in other English-speaking countries, which initially used proprietary names such as "Ballistite" and "Cordite" but gradually shifted to "propellant" as the generic term. The basis of the term smokeless is that the combustion products are mainly gaseous, compared to around 55% solid products (mostly potassium carbonate, potassium sulfate, and potassium sulfide) for black powder.〔Hatcher, Julian S. and Barr, Al ''Handloading'' Hennage Lithograph Company (1951) p.34〕 Despite its name, smokeless powder is not completely free of smoke;〔Fairfield, A. P., CDR USN ''Naval Ordnance'' Lord Baltimore Press (1921) p.44〕 while there may be little noticeable smoke from small-arms ammunition, smoke from artillery fire can be substantial. This article focuses on nitrocellulose formulations, but the term smokeless powder was also used to describe various picrate mixtures with nitrate, chlorate, or dichromate oxidizers during the late 19th century, before the advantages of nitrocellulose became evident.〔Sharpe, Philip B. ''Complete Guide to Handloading'' 3rd Edition (1953) Funk & Wagnalls pp.146-149〕 Since the 14th century〔seegunpowder〕 gunpowder was not actually a physical "powder," and smokeless powder can be produced only as a pelletized or extruded granular material. Smokeless powder allowed the development of modern semi- and fully automatic firearms and lighter breeches and barrels for artillery. Burnt black powder leaves a thick, heavy fouling that is hygroscopic and causes rusting of the barrel. The fouling left by smokeless powder exhibits none of these properties (though some primer compounds can leave hygroscopic salts that have a similar effect; non-corrosive primer compounds were introduced in the 1920s〔Sharpe, Philip B. Complete Guide To Handloading (1953) Funk & Wagnalls p.60〕〔Davis, William C., Jr. Handloading (1981) National Rifle Association p.21〕). This makes an autoloading firearm with many moving parts feasible (which would otherwise jam or seize under heavy black powder fouling). Smokeless powders are classified as, typically, division 1.3 explosives under the UN ''Recommendations on the transportation of Dangerous goods – Model Regulations'', regional regulations (such as ADR) and national regulations (such the United States' ATF). However, they are used as solid propellants; in normal use, they undergo deflagration rather than detonation. ==Background== Before the widespread introduction of smokeless powder the use of black powder caused many problems on the battlefield. Military commanders since the Napoleonic Wars reported difficulty with giving orders on a battlefield obscured by the smoke of firing. Verbal commands could not be heard above the noise of the guns, and visual signals could not be seen through the thick smoke from the gunpowder used by the guns. Unless there was a strong wind, after a few shots, soldiers using black powder ammunition would have their view obscured by a huge cloud of smoke. Snipers or other concealed shooters were given away by a cloud of smoke over the firing position. Black powder is also corrosive, making cleaning mandatory after every use. Likewise, black powder's tendency to produce severe fouling caused actions to jam and often made reloading difficult. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「smokeless powder」の詳細全文を読む スポンサード リンク
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