Editing Gun barrel (section)

== History ==
[[File:Moscow July 2011-10a.jpg|thumb|The [[Tsar Cannon]] of 1586 with its huge bore and a barrel exterior which is perceived like a stack of storage [[barrel]]s]]
[[File:The Employment of Women in Britain, 1914-1918 Q110352.jpg|thumb|A female worker boring out the barrel of a [[Lee-Enfield rifle]] during [[WWI]]]]
Gun barrels are usually made of some type of metal or [[Alloy|metal alloy]]. However, during the late [[Tang dynasty]], Chinese inventors discovered [[gunpowder]], and used [[bamboo]], which has a strong, naturally tubular stalk and is cheaper to obtain and process, as the first barrels in gunpowder projectile weapons such as [[fire lance]]s.<ref name="books.google.com">{{cite book |author=Judith Herbst |title=The History of Weapons |url=https://books.google.com/books?id=U-5T2Zs5qG8C&pg=PA8 |year=2005 |publisher=Lerner Publications |isbn=978-0-8225-3805-9 |page=8}}</ref> The Chinese were also the first to master [[cast-iron]] cannon barrels, and used the technology to make the earliest infantry firearms — the [[hand cannon]]s. Early European guns were made of [[wrought iron]], usually with several strengthening bands of the metal wrapped around circular wrought iron rings and then welded into a hollow cylinder.<ref name="Lavery1987">{{cite book |last=Lavery |first=Brian |title=The Arming and Fitting of English Ships of War, 1600-1815 |chapter-url=https://books.google.com/books?id=djwmMDm48uwC&pg=PA88|year=1987|publisher=Naval Institute Press |isbn=978-0-87021-009-9 |pages=88–90 |chapter=The Shape of Guns}}</ref> [[Bronze]] and [[brass]] were favoured by [[gunsmith]]s, largely because of their ease of casting and their resistance to the corrosive effects of the combustion of gunpowder or salt water when used on naval vessels.<ref name="Goddard2010">{{cite book |last=Goddard |first=Jolyon |title=Concise History of Science & Invention: An Illustrated Time Line |url=https://books.google.com/books?id=SuQZnlnLdc8C&pg=PA92 |year=2010 |publisher=National Geographic |isbn=978-1-4262-0544-6 |page=92}}</ref>

Early [[firearm]]s were [[muzzleloaders]], with the [[gunpowder]] and then the [[round shot|shot]] loaded from the front end (muzzle) of the barrel, and were capable of only a low [[rate of fire]] due to the cumbersome loading process. The later-invented [[breech-loading weapon|breech-loading designs]] provided a higher rate of fire, but early breechloaders lacked an effective way of sealing the escaping gases that leaked from the back end (breech) of the barrel, reducing the available [[muzzle velocity]].<ref name="James2010">{{cite book |last=James |first=Rodney |title=The ABCs Of Reloading: The Definitive Guide for Novice to Expert |url=https://books.google.com/books?id=lSngA8OgTKcC&pg=PA21 |date=15 December 2010 |publisher=Krause Publications |location=Iola, Wisconsin |isbn=978-1-4402-1787-6 |page=21}}</ref>  During the 19th century, effective [[breechblock]]s were invented that sealed a breechloader against the escape of propellant gases.<ref name="Moller2011">{{cite book |last=Moller |first=George D. |title=American Military Shoulder Arms, Volume III: Flintlock Alterations and Muzzleloading Percussion Shoulder Arms, 1840-1865 |url=https://books.google.com/books?id=y7_DzNMrDqsC&pg=PT98 |date=15 November 2011 |publisher=UNM Press |isbn=978-0-8263-5002-2 |pages=98–99}}</ref>

Early cannon barrels were very thick for their [[calibre]]. This was because manufacturing defects such as air bubbles trapped in the metal were common at that time, and played key factors in many gun explosions; these defects made the barrel too weak to withstand the pressures of firing, causing it to fail and fragment explosively.<ref name="Kinard2007">{{cite book |last=Kinard |first=Jeff |title=Artillery: An Illustrated History of Its Impact |url=https://books.google.com/books?id=iH4j8abhD1cC&pg=PA77 |year=2007 |publisher=ABC-CLIO |isbn=978-1-85109-556-8 |page=77}}</ref>