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Bourrelet
A bourrelet is a portion of an elongated artillery projectile which is used in conjunction with the projectile's driving band, or rotating band, to stabilize its flight by keeping the fore part of the projectile precisely aligned with the barrel. Details The bourrelet has a diameter very slightly smaller than the interior diameter of the barrel through which that projectile is to be propelled. It is typically precisely machined to a specified diameter after the remainder of the cast projectile body has been roughly machined to a smaller diameter. The bourrelet is normally forward of a rotating band or driving band near the aft end of the projectile. The driving band is customarily made of a softer metal than the remainder of the artillery projectile and of a larger diameter than the bourrelet to seal the barrel and be engraved by the rifling to spin-stabilize the projectile in flight. The bourrelet is not engraved by the rifling, but is supported by the lands between the rifling to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Driving Band
Russian 122 mm shrapnel shell, which has been fired, showing rifling marks on the copper driving band around its base and the steel bourrelet nearer the front A driving band or rotating band is a band of soft metal near the base of an artillery shell, often made of gilding metal, copper, or lead. When the shell is fired, the pressure of the propellant swages the metal into the rifling of the barrel and forms a seal; this seal prevents the gases from blowing past the shell, and engages the barrel's rifling to spin-stabilize the shell. Purpose The rotating band has three essential functions: * Center the rear end of the projectile in the gun barrel. * Seal the bore to prevent burning powder gas from moving through the rifling grooves past the projectile. * Engage with the rifling of the barrel to spin the projectile and stabilize its flight. Characteristics The shell is stabilized for yaw in the barrel by a smaller bourrelet band near the front of the projectile. This band ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artillery
Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and led to heavy, fairly immobile siege engines. As technology improved, lighter, more mobile field artillery cannons developed for battlefield use. This development continues today; modern self-propelled artillery vehicles are highly mobile weapons of great versatility generally providing the largest share of an army's total firepower. Originally, the word "artillery" referred to any group of soldiers primarily armed with some form of manufactured weapon or armor. Since the introduction of gunpowder and cannon, "artillery" has largely meant cannons, and in contemporary usage, usually refers to shell-firing guns, howitzers, and mortars (collectively called ''barrel artillery'', ''cannon artillery'', ''gun artillery'', or - a layman t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sabot (firearms)
A sabot (, ) is a supportive device used in firearm/artillery ammunitions to fit/patch around a projectile, such as a bullet/shotgun slug, slug or a flechette-like projectile (such as a kinetic energy penetrator), and keep it aligned in the center of the barrel (firearms), barrel when fired. It allows a narrower projectile with high sectional density to be fired through a gun barrel, barrel of much larger caliber, bore diameter with maximal acceleration, accelerative transfer of kinetic energy. After leaving the muzzle (firearms), muzzle, the sabot typically separates from the projectile in flight, diverting only a very small portion of the overall kinetic energy. The sabot component in projectile design is the relatively thin, tough and deformable seal known as a driving band or obturation ring needed to trap propellant gases behind a projectile, and also keep the projectile centered in the barrel, when the outer shell of the projectile is only slightly smaller in diameter than t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baltimore, Maryland
Baltimore ( , locally: or ) is the most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic, and the 30th most populous city in the United States with a population of 585,708 in 2020. Baltimore was designated an independent city by the Constitution of Maryland in 1851, and today is the most populous independent city in the United States. As of 2021, the population of the Baltimore metropolitan area was estimated to be 2,838,327, making it the 20th largest metropolitan area in the country. Baltimore is located about north northeast of Washington, D.C., making it a principal city in the Washington–Baltimore combined statistical area (CSA), the third-largest CSA in the nation, with a 2021 estimated population of 9,946,526. Prior to European colonization, the Baltimore region was used as hunting grounds by the Susquehannock Native Americans, who were primarily settled further northwest than where the city was later built. Colonis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yaw Angle
The Euler angles are three angles introduced by Leonhard Euler to describe the orientation of a rigid body with respect to a fixed coordinate system.Novi Commentarii academiae scientiarum Petropolitanae 20, 1776, pp. 189–207 (E478PDF/ref> They can also represent the orientation of a mobile frame of reference in physics or the orientation of a general basis in 3-dimensional linear algebra. Alternative forms were later introduced by Peter Guthrie Tait and George H. Bryan intended for use in aeronautics and engineering. Chained rotations equivalence Euler angles can be defined by elemental geometry or by composition of rotations. The geometrical definition demonstrates that three composed ''elemental rotations'' (rotations about the axes of a coordinate system) are always sufficient to reach any target frame. The three elemental rotations may be extrinsic (rotations about the axes ''xyz'' of the original coordinate system, which is assumed to remain motionless), or intrinsic ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage of its active battle fleet alone exceeding the next 13 navies combined, including 11 allies or partner nations of the United States as of 2015. It has the highest combined battle fleet tonnage (4,635,628 tonnes as of 2019) and the world's largest aircraft carrier fleet, with eleven in service, two new carriers under construction, and five other carriers planned. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the United States Navy is the third largest of the United States military service branches in terms of personnel. It has 290 deployable combat vessels and more than 2,623 operational aircraft . The United States Navy traces its origins to the Continental Navy, which was established during the American Revo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sub-caliber Round
Sub-caliber ammunition is firearm ammunition where the projectile has a smaller diameter than the bore of the gun barrel from which it is fired. Firing sub-caliber ammunition has several potential benefits compared to full-caliber ammunition. It can for example allow for much higher muzzle velocities due to smaller lighter projectiles being fired from relatively larger propellant charges, but it can also lower the cost of ammunition due to less material being used to produce the round compared to a full-caliber ammunition etc. Several methods exists to be able to fire sub-caliber ammunition. Sabot method The most traditional way to fire sub-caliber ammunition is to fit the projectile with an expendable sabot. The sabot is a device which fills out the missing caliber when the projectile is fired and then leaves the projectile once it has left the barrel. File:Sabot Diagram Example.png, Diagram of the sabot method Saboted sub-caliber ammunition types * Flechette *Armour-pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
