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Gun barrel
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<h2 id="history">History</h2> <p>Gun barrels are usually made of some type of metal or <a href="/facts/Alloy/I7w7WQWR">metal alloy</a>. However, during the late <a href="/facts/Tang_dynasty/FFhmVfwM">Tang dynasty</a>, Chinese inventors discovered <a href="/facts/Gunpowder/AEcB6HCR">gunpowder</a>, and used <a href="/facts/Bamboo/wGPJ2cEA">bamboo</a>, which has a strong, naturally tubular stalk and is cheaper to obtain and process, as the first barrels in gunpowder projectile weapons such as <a href="/facts/Fire_lance/aKjj1YaR">fire lances</a>.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> The Chinese were also the first to master <a href="/facts/Cast-iron/lASt55k2">cast-iron</a> cannon barrels, and used the technology to make the earliest infantry firearms — the <a href="/facts/Hand_cannon/5rGD3tEL">hand cannons</a>. Early European guns were made of <a href="/facts/Wrought_iron/zynpjrIv">wrought iron</a>, usually with several strengthening bands of the metal wrapped around circular wrought iron rings and then welded into a hollow cylinder.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> <a href="/facts/Bronze/YCYCVIKt">Bronze</a> and <a href="/facts/Brass/pe8EHk6x">brass</a> were favoured by <a href="/facts/Gunsmith/qGSrJIEX">gunsmiths</a>, 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.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> </p><p>Early <a href="/facts/Firearm/GuHx4aGE">firearms</a> were <a href="/facts/Muzzleloaders/RpJPVv78">muzzleloaders</a>, with the <a href="/facts/Gunpowder/AEcB6HCR">gunpowder</a> and then the <a href="/facts/Round_shot/SGXTvIIv">shot</a> loaded from the front end (muzzle) of the barrel, and were capable of only a low <a href="/facts/Rate_of_fire/QJAEvtyP">rate of fire</a> due to the cumbersome loading process. The later-invented <a href="/facts/Breech-loading_weapon/bCzCKg7n">breech-loading designs</a> 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 <a href="/facts/Muzzle_velocity/RHSvMT4D">muzzle velocity</a>.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> During the 19th century, effective <a href="/facts/Breechblock/mkVuRPHK">breechblocks</a> were invented that sealed a breechloader against the escape of propellant gases.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> </p><p>Early cannon barrels were very thick for their <a href="/facts/Calibre/q4hhaID2">calibre</a>. 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.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> </p> <h2 id="construction">Construction</h2> <p>A gun barrel must be able to hold in the expanding gas produced by the <a href="/facts/Propellant/K88ymXRy">propellants</a> to ensure that optimum <a href="/facts/Muzzle_velocity/RHSvMT4D">muzzle velocity</a> is attained by the projectile as it is being pushed out. If the barrel material cannot cope with the pressure within the bore, the barrel itself might suffer <a href="/facts/Catastrophic_failure/X5NDNv9r">catastrophic failure</a> and explode, which will not only destroy the gun but also present a life-threatening danger to people nearby. Modern <a href="/facts/Small_arms/GuHx4aGE">small arms</a> barrels are made of <a href="/facts/Carbon_steel/QGYURvFA">carbon steel</a> or <a href="/facts/Stainless_steel/IDdo8bEx">stainless steel</a> materials known and tested to withstand the pressures involved. Artillery pieces are made by various techniques providing reliably sufficient strength.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a><a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> </p> <h3>Fluting</h3> <p class="note">Main article: <a href="/facts/Fluting_(firearms)/7DHdE8AA">Fluting (firearms)</a></p> <p>Fluting is the removal of material from a cylindrical surface, usually creating rounded grooves, for the purpose of reducing weight. This is most often done to the exterior surface of a rifle barrel, though it may also be applied to the <a href="/facts/Cylinder_(firearms)/3bAssURv">cylinder</a> of a <a href="/facts/Revolver/cPKNksV8">revolver</a> or the <a href="/facts/Bolt_(firearms)/mEpdypQk">bolt</a> of a <a href="/facts/Bolt-action_rifle/yEy9pnyG">bolt-action rifle</a>. Most flutings on rifle barrels and revolver cylinders are straight, though helical flutings can be seen on rifle bolts and occasionally also rifle barrels. </p><p>While the main purpose of fluting is just to reduce weight and improve portability, when adequately done it can retain the <a href="/facts/Strength_of_materials/CE77cUcB">structural strength</a> and <a href="/facts/Stiffness/xlabLkfT">rigidity</a> and increase the overall <a href="/facts/Specific_strength/D3nbocax">specific strength</a>. Fluting will also increase the <a href="/facts/Surface-to-volume_ratio/lEl1rKLh">surface-to-volume ratio</a> and make the barrel more efficient to cool after firing, though the reduced material mass also means the barrel will heat up easily during firing. </p> <h3>Composite barrels</h3> <p>A composite barrel is a firearm barrel that has been shaved down to be thinner and an exterior sleeve slipped over and fused to it that improves rigidity, weight and cooling. Most common form of composite barrel are those with <a href="/facts/Carbon_fibre/6PlL4mB2">carbon fibre</a> sleeves, but there are proprietary examples such as the Teludyne Tech Straitjacket. They are seldom used outside <a href="/facts/Shooting_sports/BjN81VcD">sports and competition shooting</a>. </p> <h2 id="mounting">Mounting</h2> <p>A barrel can be fixed to the receiver using <a href="/facts/Action_threads/dnzUUfwk">action threads</a> or rivets. Depending on construction different gun barrels can be used: </p> <ul><li>common fixed barrel for firearms</li> <li>interchangeable barrel for firearms</li> <li>quick-change barrel for machineguns</li> <li>replacement gun barrel (spare barrel) for artilleryguns</li></ul> <h2 id="components">Components</h2> <h3>Chamber</h3> <p class="note">Main article: <a href="/facts/Chamber_(firearms)/X1Ekw5aK">Chamber (firearms)</a></p> <p>The chamber is the cavity at the back end of a <a href="/facts/Breech-loading_gun/bCzCKg7n">breech-loading gun</a>'s barrel where the <a href="/facts/Cartridge_(firearms)/vjkWaDjM">cartridge</a> is inserted in position ready to be fired. In most firearms (<a href="/facts/Rifle/H3mJx7U4">rifles</a>, <a href="/facts/Shotgun/tGxz1bqj">shotguns</a>, <a href="/facts/Machine_gun/JPXmy1zR">machine guns</a> and <a href="/facts/Pistol/pQgRhGBM">pistols</a>), the chamber is an integral part of the barrel, often made by simply <a href="/facts/Reaming/GLdAdalF">reaming</a> the rear bore of a barrel blank, with a single chamber within a single barrel.<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> In <a href="/facts/Revolver/cPKNksV8">revolvers</a>, the chamber is a component of the gun's <a href="/facts/Cylinder_(firearms)/3bAssURv">cylinder</a> and completely separate from the barrel, with a single cylinder having multiple chambers that are rotated in turns into alignment with the barrel in anticipation of being fired. </p><p>Structurally, the chamber consists of the body, shoulder and neck, the contour of which closely correspond to the casing shape of the cartridge it is designed to hold. The rear opening of the chamber is the breech of the whole barrel, which is sealed tight from behind by the <a href="/facts/Bolt_(firearms)/mEpdypQk">bolt</a>, making the front direction the <a href="/facts/Path_of_least_resistance/erQgmE8a">path of least resistance</a> during firing. When the cartridge's <a href="/facts/Primer_(firearm)/AcMqsCQR">primer</a> is struck by the <a href="/facts/Firing_pin/KGKtHjFo">firing pin</a>, the <a href="/facts/Propellant/K88ymXRy">propellant</a> is ignited and <a href="/facts/Deflagrate/wIR4pGtC">deflagrates</a>, generating high-pressure gas expansion within the cartridge case. However, the chamber (closed from behind by the bolt) restrains the cartridge case (or <a href="/facts/Shotgun_shell/YABrvUeX">shell</a> for shotguns) from moving, allowing the <a href="/facts/Bullet/VgJXCI0b">bullet</a> (or <a href="/facts/Shot_(pellet)/DR9Gf5qm">shot</a>/<a href="/facts/Shotgun_slug/eqPf0L1j">slug</a> in shotguns) to separate cleanly from the casing and be propelled forward along the barrel to exit out of the front (muzzle) end as a flying <a href="/facts/Projectile/kaDpG3N7">projectile</a>. </p><p>Chambering a gun is the process of loading a cartridge into the gun's chamber, either manually as in <a href="/facts/Single_shot/sbk1Pdjo">single loading</a>, or via operating the weapon's own <a href="/facts/Action_(firearms)/R2APeqab">action</a> as in <a href="/facts/Pump_action/Uc6vJDyL">pump action</a>, <a href="/facts/Lever_action/gYhgnSxR">lever action</a>, <a href="/facts/Bolt_action/yEy9pnyG">bolt action</a> or <a href="/facts/Self-loading/2mTJkWwp">self-loading</a> actions. In the case of an <a href="/facts/Air_gun/E2MPVHEA">air gun</a>, a pellet (or slug) itself has no casing to be retained and will be entirely inserted into the chamber (often called "seating" or "loading" the pellet, rather than "chambering" it) before a mechanically pressurized gas is released behind the pellet and propels it forward, meaning that an air gun's chamber is functionally equivalent to the freebore portion of a firearm barrel. </p><p>In the context of firearms design, manufacturing and modification, the word "chambering" has a different meaning, and refers to fitting a weapon's chamber specifically to fire a particular <a href="/facts/Caliber/q4hhaID2">caliber</a> or model of cartridge. </p> <h3>Bore</h3> <p class="note">See also: <a href="/facts/Internal_ballistics/zynpU5yg">Internal ballistics</a>, <a href="/facts/Rifling/63UWYEdX">Rifling</a>, and <a href="/facts/Freebore/cmH7nYMe">Freebore</a></p> <p>The bore is the hollow internal <a href="/facts/Lumen_(anatomy)/3thJT4Hf">lumen</a> of the barrel, and takes up a vast majority portion of the barrel length. It is the part of the barrel where the projectile (bullet, shot, or slug) is located prior to firing and where it gains <a href="/facts/Speed/I3qgMPfs">speed</a> and <a href="/facts/Kinetic_energy/aJRxUd4p">kinetic energy</a> during the firing process. The projectile's status of <a href="/facts/Motion_(physics)/dCnP7MlB">motion</a> while travelling down the bore is referred to as its <a href="/facts/Internal_ballistics/zynpU5yg">internal ballistics</a>. </p><p>Most modern firearms (except <a href="/facts/Musket/YmnMv1F2">muskets</a>, shotguns, most <a href="/facts/Tank_gun/SsQYdota">tank guns</a>, and some <a href="/facts/Artillery_piece/GLpMYG9o">artillery pieces</a>) and air guns (except some <a href="/facts/BB_gun/A1Iy039k">BB guns</a>) have helical grooves called <i>riflings</i> machined into the bore wall. When shooting, a rifled bore imparts spin to the projectile about its longitudinal axis, which <a href="/facts/Gyroscopic/UjXGsfMq">gyroscopically</a> stabilizes the projectile's <a href="/facts/Projectile_motion/yBGsDIGe">flight</a> <a href="/facts/Attitude_(geometry)/Tj24mTJ8">attitude</a> and <a href="/facts/Trajectory/STNN33FK">trajectory</a> after its exit from the barrel (i.e. the <a href="/facts/External_ballistics/cF2PHJ4W">external ballistics</a>). Any gun without riflings in the bore is called a <i><a href="/facts/Smoothbore/T6z0unC3">smoothbore</a></i> gun. </p><p>When a firearm cartridge is chambered, its casing occupies the chamber but its bullet actually protrudes beyond the chamber into the posterior end of the bore. Even in a rifled bore, this short rear section is without rifling, and allows the bullet an initial "run-up" to build up <a href="/facts/Momentum/TTkGv5eY">momentum</a> before encountering riflings during shooting. The most posterior part of this unrifled section is called a <i>freebore</i>, and is usually cylindrical. The portion of the unrifled bore immediately front of the freebore, called the <i>leade</i>, starts to taper slightly and guides the bullet towards the area where the riflingless bore transitions into fully rifled bore. Together they form the throat region, where the riflings impactfully "bite" into the moving bullet during shooting. The throat is subjected to the greatest thermomechanical <a href="/facts/Stress_(mechanics)/ErAXDbbd">stress</a> and therefore suffers <a href="/facts/Wear/2PxRQ1Ke">wear</a> the fastest. Throat erosion is often the main determining factor of a gun's barrel life. </p> <h3>Muzzle</h3> <p class="note">See also: <a href="/facts/Transitional_ballistics/xQpQ7ghV">Transitional ballistics</a></p> <p>The muzzle is the front end of a barrel from which the projectile will exit.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> Precise <a href="/facts/Machining/Yrjfj6IV">machining</a> of the muzzle is crucial to accuracy, because it is the last point of contact between the barrel and the projectile. If inconsistent gaps exist between the muzzle and the projectile, escaping propellant gases may spread unevenly and deflect the projectile from its intended path (see <a href="/facts/Transitional_ballistics/xQpQ7ghV">transitional ballistics</a>). The muzzle can also be <a href="/facts/Threading_(manufacturing)/lP5J2kou">threaded</a> on the outside to allow the attachment of different accessory devices. </p><p>In <a href="/facts/Rifling/63UWYEdX">rifled</a> barrels, the contour of a muzzle is designed to keep the rifling safe from damage by intruding foreign objects, so the front ends of the rifling grooves are commonly protected behind a recessed crown, which also serves to modulate the even expansion of the propellant gases. The crown itself is often recessed from the outside rim of the muzzle to avoid accidental damage from collision with the surrounding environment. </p><p>In <a href="/facts/Smooth_bore/T6z0unC3">smooth bore</a> barrels firing multiple sub-projectiles (such as shotgun shot), the bore at the muzzle end might have a tapered constriction called <i><a href="/facts/Choke_(firearms)/DHXVedr3">choke</a></i> to shape the scatter pattern for better range and accuracy. Chokes are implemented as either interchangeable screw-in chokes for particular applications, or as fixed permanent chokes integral to the barrel. </p><p>During firing, a bright flash of light known as a <i><a href="/facts/Muzzle_flash/M6apgBXV">muzzle flash</a></i> is often seen at the muzzle. This flash is produced by both superheated propellant gases radiating energy during expansion (primary flash), and the incompletely combusted <a href="/facts/Gunshot_residue/TLrWvfsr">propellant residues</a> reacting vigorously with the fresh supply of ambient air upon escaping the barrel (secondary flash). The size of the flash depends on factors such as barrel length (shorter barrels have less time for complete combustion, hence more unburnt powder), the type (fast- vs. slow-burning) and amount of propellant (higher total amount means likely more unburnt residues) loaded in the cartridge. <a href="/facts/Flash_suppressor/jwqQSPHb">Flash suppressors</a> or <a href="/facts/Muzzle_shroud/UGXsjRKC">muzzle shrouds</a> can be attached to the muzzle of the weapon to either diminish or conceal the flash.<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> </p><p>The rapid expansion of propellant gases at the muzzle during firing also produce a powerful <a href="/facts/Shockwave/CqrG1Xm5">shockwave</a> known as a <i><a href="/facts/Muzzle_blast/a8LS3HJq">muzzle blast</a></i>. The audible component of this blast, also known as a <i>muzzle report</i>, is the loud "bang" sound of gunfire that can easily exceed 140 <a href="/facts/Decibel/0LyxAPXh">decibels</a> and cause permanent <a href="/facts/Noise-induced_hearing_loss/3fvhFuDv">hearing loss</a> to the shooter and bystanders. The non-audible component of the blast is an <a href="/facts/Infrasonic/yCUJSSe3">infrasonic</a> <a href="/facts/Overpressure/aepmRBw0">overpressure</a> wave that can cause damage to nearby fragile objects. Accessory devices such as <a href="/facts/Muzzle_brake/RrBz5bGs">muzzle brakes</a> and <a href="/facts/Muzzle_booster/91aQRtzS">muzzle boosters</a> can be used to redirect muzzle blast in order to counter the <a href="/facts/Recoil/wGukfupU">recoil</a>-induced <a href="/facts/Muzzle_rise/Irhrl4rY">muzzle rise</a> or to assist the <a href="/facts/Gas_operation/CnKcFREy">gas operation</a> of the gun, and <a href="/facts/Suppressor/ok8jwWHM">suppressors</a> (and even muzzle shrouds) can be used to reduce the blast <a href="/facts/Sound_intensity/c9KFwjYL">noise intensity</a> felt by nearby personnel. </p> Barrel componentsChamberBoreMuzzle <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Bore_evacuator/rl1fkMz7">Bore evacuator</a></li> <li><a href="/facts/Bore_snake/pEelbL89">Bore snake</a></li> <li><a href="/facts/Cap_gun/xKSbonLG">Cap gun</a></li> <li><a href="/facts/Caplock_mechanism/kvj5E8ac">Caplock mechanism</a></li> <li><a href="/facts/Mini%25C3%25A9_ball/c7bYIvLh">Minié ball</a></li> <li><a href="/facts/Muzzleloader/RpJPVv78">Muzzleloader</a></li> <li><a href="/facts/Polygonal_rifling/UtzY0orz">Polygonal rifling</a></li> <li><a href="/facts/Slug_barrel/xCNqLLNk">Slug barrel</a></li> <li><a href="/facts/Smoothbore/T6z0unC3">Smoothbore</a> barrel, opposite of a <a href="/facts/Rifling/63UWYEdX">rifling</a> barrel</li> <li><a href="/facts/Tubes_and_primers_for_ammunition/yN2lshK5">Tubes and primers for ammunition</a></li></ul> Wikimedia Commons has media related to Gun barrels. <h2 id="bibliography">Bibliography</h2> <ul><li>Quertermous, Russell C.; Quertermous, Steven C. (1981). <i>Modern Guns</i> (Revised 3rd ed.). Paducah, Kentucky: Collector Books. <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 0-89145-146-3.</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>A History of Warfare – Keegan, John, Vintage 1993. <a href="/wiki/A_History_of_Warfare" target="_blank">/wiki/A_History_of_Warfare</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Judith Herbst (2005). The History of Weapons. Lerner Publications. p. 8. ISBN 978-0-8225-3805-9. <a href="978-0-8225-3805-9" target="_blank">978-0-8225-3805-9</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Lavery, Brian (1987). "The Shape of Guns". The Arming and Fitting of English Ships of War, 1600-1815. Naval Institute Press. pp. 88–90. ISBN 978-0-87021-009-9. <a href="978-0-87021-009-9" target="_blank">978-0-87021-009-9</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Goddard, Jolyon (2010). Concise History of Science & Invention: An Illustrated Time Line. National Geographic. p. 92. ISBN 978-1-4262-0544-6. <a href="978-1-4262-0544-6" target="_blank">978-1-4262-0544-6</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>James, Rodney (15 December 2010). The ABCs Of Reloading: The Definitive Guide for Novice to Expert. Iola, Wisconsin: Krause Publications. p. 21. ISBN 978-1-4402-1787-6. <a href="978-1-4402-1787-6" target="_blank">978-1-4402-1787-6</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Moller, George D. (15 November 2011). American Military Shoulder Arms, Volume III: Flintlock Alterations and Muzzleloading Percussion Shoulder Arms, 1840-1865. UNM Press. pp. 98–99. ISBN 978-0-8263-5002-2. <a href="978-0-8263-5002-2" target="_blank">978-0-8263-5002-2</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Kinard, Jeff (2007). Artillery: An Illustrated History of Its Impact. ABC-CLIO. p. 77. ISBN 978-1-85109-556-8. <a href="978-1-85109-556-8" target="_blank">978-1-85109-556-8</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Weir, William (2005). 50 Weapons That Changed Warfare. Career Press. p. 131. ISBN 978-1-56414-756-1. <a href="978-1-56414-756-1" target="_blank">978-1-56414-756-1</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Payne, Craig M. (2006). Principles of Naval Weapon Systems. Naval Institute Press. p. 263. ISBN 978-1-59114-658-2. <a href="978-1-59114-658-2" target="_blank">978-1-59114-658-2</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>"Method of manufacturing gun barrels". <a href="https://patents.google.com/patent/US2901814A/en" target="_blank">https://patents.google.com/patent/US2901814A/en</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Quertermous & Quertermous, p. 429 f. <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>Quertermous & Quertermous, p. 429 f. <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> </ol>