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Rotation Of Ammunition
''Rotation of ammunition'' is a term used with reference to guns. Projectiles intended for RML (rifled muzzle-loading) guns were at first fitted with a number of gun-metal studs arranged around them in a spiral manner corresponding to the twist of rifling. Invented in mid-1840s by Giovanni Cavalli, this method was defective, as it allowed, as in the old smooth-bore guns, the powder gas to escape by the clearance (called "windage") between the projectile and the bore, with a consequent loss of efficiency; it also quickly eroded the bore of the larger guns. Multiple solution to the problems were invented in two following decades, both for muzzle-loaders and breech-loaders. In 1855 Andrew Hotchkiss patented an RML projectile, in which two parts squeezed a lead ring to obturate the barrel under the pressure of gunpowder fumes. After his death in 1858 his brother Benjamin, later a renowned arms designer and industrialist, adapted the design to practical use, and the Union Army fired ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Projectiles With Copper Rings - The Engineer 1908-11-20
A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found in warfare and sports (for example, a thrown baseball, kicked football, fired bullet, shot arrow, stone released from catapult). In ballistics mathematical equations of motion are used to analyze projectile trajectories through launch, flight, and impact. Motive force Blowguns and pneumatic rifles use compressed gases, while most other guns and cannons utilize expanding gases liberated by sudden chemical reactions by propellants like smokeless powder. Light-gas guns use a combination of these mechanisms. Railguns utilize electromagnetic fields to provide a constant acceleration along the entire length of the device, greatly increasing the muzzle velocity. Some projectiles provide propulsion during flight by means of a rocket engine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas-checks In British RML Heavy Guns
Gas-checks were attachments to ammunition that revolutionised the performance of RML heavy guns. The first generation of RML heavy guns began entering service in about 1865. They all had Woolwich rifling and relied on studs on the projectiles for rotation. Gas-checks were first introduced in 1878 or soon after. They significantly reduced wear on the guns while also increasing their range and accuracy. Before long, studless ammunition was being manufactured for these guns, using gas-checks for projectile rotation. Gas-checks also facilitated a switch to the second generation of RML guns which used polygroove rifling and only supported studless ammunition. Introduction The first RML heavy guns were introduced into British service in about 1865. By 1878, 11 models of Woolwich rifled guns had been introduced, ranging from 7 inches to 12.5 inches. Unfortunately, Woolwich rifling had a major defect, namely, that hot powder gas escaping around the ammunition ("Windage Windage is a term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and even by industry. Further, both spellings are often used ''within'' a particular industry or country. Industries in British English-speaking countries typically use the "gauge" spelling. is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch ( psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as of this. Manome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding (motion), sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into ''static friction'' ("stiction") between non-moving surfaces, and ''kinetic friction'' between moving surfaces. With the exception of atomic or molecular friction, dry friction generally arises from the interaction of surface features, known as Asperity (materials science), asperities (see Figure 1). *Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. *Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. *Skin friction is a component of Drag (physics), drag, the force resisting the motion of a fluid across the surface of a body. *Internal friction is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be * chemical energy, such as nitroglycerin or grain dust * pressurized gas, such as a gas cylinder, aerosol can, or BLEVE * nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239 Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and materials that deflagrate are said to be "low explosives". Explosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
