The Korean War was a war between North Korea and South Korea. The war began on 25 June 1950 when North Korea invaded South Korea following a series of clashes along the border; as a product of the Cold War between the Soviet Union and the United States, Korea had been split into two sovereign states in 1948. A socialist state was established in the north under the communist leadership of Kim Il-sung and a capitalist state in the south under the anti-communist leadership of Syngman Rhee. Both governments of the two new Korean states claimed to be the sole legitimate government of all of Korea, neither accepted the border as permanent; the conflict escalated into warfare when North Korean military forces—supported by the Soviet Union and China—crossed the border and advanced south into South Korea on 25 June 1950. The United Nations Security Council authorized the formation and dispatch of UN forces to Korea to repel what was recognized as a North Korean invasion. Twenty-one countries of the United Nations contributed to the UN force, with the United States providing around 90% of the military personnel.
After the first two months of war, South Korean and U. S. forces dispatched to Korea were on the point of defeat, forced back to a small area in the south known as the Pusan Perimeter. In September 1950, an amphibious UN counter-offensive was launched at Incheon, cut off many North Korean troops; those who escaped envelopment and capture were forced back north. UN forces approached the Yalu River—the border with China—but in October 1950, mass Chinese forces crossed the Yalu and entered the war; the surprise Chinese intervention triggered a retreat of UN forces which continued until mid-1951. In these reversals of fortune, Seoul changed hands four times, the last two years of fighting became a war of attrition, with the front line close to the 38th parallel; the war in the air, was never a stalemate. North Korea was subject to a massive bombing campaign. Jet fighters confronted each other in air-to-air combat for the first time in history, Soviet pilots covertly flew in defense of their communist allies.
The fighting ended on 27 July 1953. The agreement created the Korean Demilitarized Zone to separate North and South Korea, allowed the return of prisoners. However, no peace treaty was signed, according to some sources the two Koreas are technically still at war, engaged in a frozen conflict. In April 2018, the leaders of North and South Korea met at the demilitarized zone and agreed to work towards a treaty to formally end the Korean War. In South Korea, the war is referred to as "625" or the "6–2–5 Upheaval", reflecting the date of its commencement on June 25. In North Korea, the war is referred to as the "Fatherland Liberation War" or alternatively the "Chosǒn War". In China, the war is called the "War to Resist America and Aid Korea", although the term "Chaoxian War" is used in unofficial contexts, along with the term "Hán War" more used in regions such as Hong Kong and Macau. In the U. S. the war was described by President Harry S. Truman as a "police action" as the United States never formally declared war on its opponents and the operation was conducted under the auspices of the United Nations.
It has been referred to in the English-speaking world as "The Forgotten War" or "The Unknown War" because of the lack of public attention it received both during and after the war, in relation to the global scale of World War II, which preceded it, the subsequent angst of the Vietnam War, which succeeded it. Imperial Japan destroyed the influence of China over Korea in the First Sino-Japanese War, ushering in the short-lived Korean Empire. A decade after defeating Imperial Russia in the Russo-Japanese War, Japan made Korea its protectorate with the Eulsa Treaty in 1905 annexed it with the Japan–Korea Annexation Treaty in 1910. Many Korean nationalists fled the country; the Provisional Government of the Republic of Korea was founded in 1919 in Nationalist China. It failed to achieve international recognition, failed to unite nationalist groups, had a fractious relationship with its U. S.-based founding president, Syngman Rhee. From 1919 to 1925 and beyond, Korean communists led internal and external warfare against the Japanese.
In China, the Nationalist National Revolutionary Army and the communist People's Liberation Army helped organize Korean refugees against the Japanese military, which had occupied parts of China. The Nationalist-backed Koreans, led by Yi Pom-Sok, fought in the Burma Campaign; the communists, led by Kim Il-sung among others, fought the Japanese in Manchuria. At the Cairo Conference in November 1943, the United Kingdom, the United States all decided that "in due course Korea shall become free and independent". At the Tehran Conference in November 1943 and the Yalta Conference in February 1945, the Soviet Union promised to join its allies in the Pacific War within three months of the victory in Europe. Accordingly, it declared war o
A revolver is a repeating handgun that has a revolving cylinder containing multiple chambers and at least one barrel for firing. The revolver allows the user to fire multiple rounds without reloading after every shot, unlike older single shot firearms. After a round is fired the hammer is cocked and the next chamber in the cylinder is aligned with the barrel by the shooter either manually pulling the hammer back or by rearward movement of the trigger. Revolvers still remain popular as back-up and off-duty handguns among American law enforcement officers and security guards and are still common in the American private sector as defensive and sporting/hunting firearms. Famous and iconic revolvers models include the Colt 1851 Navy Revolver, the Webley, the Colt Single Action Army, the Colt Official Police, Smith & Wesson Model 10, the Smith and Wesson Model 29 of Dirty Harry fame, the Nagant M1895. Though revolvers are referred to as and are handguns, other firearms may have a revolver action.
These include some models of grenade launchers, shotguns and cannons, such as revolver cannon. These are different from other firearms with revolving chambers, such as Gatling-style rotary cannons in that revolvers require the hammer to be re-cocked with each shot and require manual reloading, while guns like the minigun are motor driven and have a barrel for each chamber. In the development of firearms, an important limiting factor was the time it took to reload the weapon after it was fired. While the user was reloading, the weapon was useless, an adversary might be able to take advantage of the situation and kill or wound the user. Several approaches to the problem of increasing the rate of fire were developed, the earliest being multi-barrelled weapons which allowed two or more shots without reloading. Weapons featured multiple barrels revolving along a single axis. During the late 16th century in China, Zhao Shi-zhen invented the Xun Lei Chong, a five-barreled musket revolver spear. Around the same time, the earliest examples of what today is called a revolver were made in Germany.
These weapons featured a single barrel with a revolving cylinder holding the ball. They would soon be made in numerous designs and configurations. However, these weapons were difficult to use and prohibitively expensive to make, as such they were not distributed. In 1836, an American, Samuel Colt, patented the mechanism which led to the widespread use of the revolver, the mechanically indexing cylinder. According to Samuel Colt, he came up with the idea for the revolver while at sea, inspired by the capstan, which had a ratchet and pawl mechanism on it, a version of, used in his guns to rotate the cylinder by cocking the hammer; this provided a reliable and repeatable way to index each round and did away with the need to manually rotate the cylinder. Revolvers proliferated due to Colt's ability as a salesman, but his influence spread in other ways as well. Early revolvers were caplocks and loaded as a muzzle-loader: the user poured black powder into each chamber, rammed down a bullet on top of it placed percussion caps on the nipple at the rear of each chamber, where the hammer would fall on it.
This was similar to loading a traditional single-shot muzzle-loading pistol, except that the powder and shot could be loaded directly into the front of the cylinder rather than having to be loaded down the whole length of the barrel. This allowed the barrel itself to be rifled, since the user wasn't required to force the tight fitting bullet down the barrel in order to load it; when firing the next shot, the user would raise his pistol vertically as he cocked the hammer back so as to let the fragments of the burst percussion cap fall out so as to not jam the mechanism. Some of the most popular cap-and-ball revolvers were the Colt Model 1851 "Navy" Model, 1860 "Army" Model, Colt Pocket Percussion revolvers, all of which saw extensive use in the American Civil War. Although American revolvers were the most common, European arms makers were making numerous revolvers by that time as well, many of which found their way into the hands of the American forces, including the single action Lefaucheux and LeMat revolver and the Beaumont–Adams and Tranter revolvers, which were early double-action weapons, in spite of being muzzle-loaders.
In 1854, Eugene Lefaucheux introduced the Lefaucheux Model 1854, the first revolver to use self-contained metallic cartridges rather than loose powder, pistol ball, percussion caps. It is a pinfire revolver holding six rounds. On November 17, 1856, Daniel B. Wesson and Horace Smith signed an agreement for the exclusive use of the Rollin White Patent at a rate of 25 cents for every revolver. Smith & Wesson began production late in 1857 and enjoyed years of exclusive production of rear-loading cartridge revolvers in America, due to their association with Rollin White, who held the patent and vigorously defended it against any perceived infringement by other manufacturers. Although White held the patent, other manufacturers were able to sell firearms using the design, provided they were willing to pay royalties. After White's patent expired in April 1869, a 3rd extension was refused. Other gun-makers wer
The Webley Revolver was, in various marks, a standard issue service pistol for the armed forces of the United Kingdom, the British Empire and Commonwealth, from 1887 until 1963. The Webley is a top-break revolver and breaking the revolver operates the extractor, which removes cartridges from the cylinder; the Webley Mk I service revolver was adopted in 1887 and the Mk IV rose to prominence during the Boer War of 1899–1902. The Mk VI, introduced in 1915 during the First World War, is the best-known model. Firing large.455 Webley cartridges, Webley service revolvers are among the most powerful top-break revolvers produced. The.455 calibre Webley is no longer in military service but the.38/200 Webley Mk IV variant is still in use as a police sidearm in a number of countries. With a modified, "shaved" cylinder and the use of a half moon clip, the Webley Mk VI can fire the.45 ACP cartridge, although standard pressure.45 ACP cartridges exceed Webley proof loads and should not be used. The British company Webley & Scott produced a range of revolvers from the mid 19th to late 20th centuries.
As early as 1853 P. Webley and J. Webley began production of their first patented single action cap and ball revolvers. Under the trade name of P. Webley and Son, manufacturing included their own.44-caliber rim-fire solid frame revolver as well as licensed copies of Smith & Wesson's Tip up break action revolvers. The quintessential hinged frame, centre-fire revolvers for which the Webley name is best known first began production/development in the early 1870s most notably with the Webley-Pryse and Webley-Kaufman models; the W. G. or Webley-Government models produced from 1885 through to the early 1900s, are the most popular of the commercial top break revolvers and many were the private purchase choice of English military officers and target shooters in the period, coming in a.476/.455 calibre. However other short-barrel solid-frame revolvers, including the Webley RIC model and the British Bulldog revolver, designed to be carried in a coat pocket for self-defence were far more commonplace during the period.
Today, undoubtedly best-known are the range of military revolvers, which were in service use across two World Wars and numerous colonial conflicts. In 1887, the British Army was searching for a revolver to replace the unsatisfactory.476 Enfield Mk I & Mk II Revolvers, the Enfield having only replaced the solid frame Adams.450 revolver, a late 1860s conversion of the cap and ball Beaumont–Adams revolver in 1880. Webley & Scott, who were very well known makers of quality guns and had sold many pistols on a commercial basis to military officers and civilians alike, tendered the.455 calibre Webley Self-Extracting Revolver for trials. The military was suitably impressed with the revolver, it was adopted on 8 November 1887 as the "Pistol, Webley, Mk I"; the initial contract called for 10,000 Webley revolvers, at a price of £3/1/1 each, with at least 2,000 revolvers to be supplied within eight months. The Webley revolver went through a number of changes, culminating in the Mk VI, in production between 1915 and 1923.
The large.455 Webley revolvers were retired in 1947, although the Webley Mk IV.38/200 remained in service until 1963 alongside the Enfield No. 2 Mk I revolver. Commercial versions of all Webley service revolvers were sold on the civilian market, along with a number of similar designs that were not adopted for service, but were nonetheless purchased by military officers; the Webley records show the last Mk VI being sold from the factory being in 1957 with "Nigeria" noted against the entry. The Webley Mk IV, chambered in.455 Webley, was introduced in 1899 and soon became known as the "Boer War Model", on account of the large numbers of officers and non-commissioned officers who purchased it on their way to take part in the conflict. The Webley Mk IV served alongside a large number of other handguns, including the Mauser C96 "Broomhandle", earlier Beaumont–Adams cartridge revolvers, other top-break revolvers manufactured by gunmakers such as William Tranter, Kynoch; the standard-issue Webley revolver at the outbreak of the First World War was the Webley Mk V, but there were more Mk IV revolvers in service in 1914, as the initial order for 20,000 Mk V revolvers had not been completed when hostilities began.
On 24 May 1915, the Webley Mk VI was adopted as the standard sidearm for British and Commonwealth troops and remained so for the duration of the First World War, being issued first to officers and range takers, to airmen, naval crews, boarding parties, trench raiders, machine-gun teams, tank crews. The Mk VI proved to be a reliable and hardy weapon, well suited to the mud and adverse conditions of trench warfare, several accessories were developed for the Mk VI, including a bayonet, speedloader devices, a stock allowing for the revolver to be converted into a carbine. Demand exceeded production, behind as the war began; this forced the British government to buy substitute weapons chambered in.455 Webley from neutral countries. America provided the Wesson 2nd Model "Hand Ejector" and Colt New Service Revolvers. Spani
Lee Harvey Oswald
Lee Harvey Oswald was an American Marxist and former U. S. Marine who assassinated United States President John F. Kennedy on November 22, 1963. Oswald was honorably released from active duty in the Marine Corps into the reserve and defected to the Soviet Union in October 1959, he lived in the Belarusian city of Minsk until June 1962, when he returned to the United States with his Russian wife and settled in Dallas. Five government investigations concluded that Oswald shot and killed Kennedy from the sixth floor of the Texas School Book Depository as the President traveled by motorcade through Dealey Plaza in Dallas, Texas. About 45 minutes after assassinating Kennedy, Oswald shot and killed Dallas police officer J. D. Tippit on a local street, he slipped into a movie theater, where he was arrested for Tippit's murder. Oswald was charged with the assassination of Kennedy. Two days Oswald was fatally shot by local nightclub owner Jack Ruby on live television in the basement of Dallas Police Headquarters.
In September 1964, the Warren Commission concluded that Oswald acted alone when he assassinated Kennedy by firing three shots from the Texas School Book Depository. This conclusion, though controversial, was supported by previous investigations from the FBI, the Secret Service, the Dallas Police Department. Despite forensic and eyewitness evidence supporting the official findings, public opinion polls have shown that most Americans do not believe the official version of the events; the assassination has spawned numerous conspiracy theories. Oswald was born in New Orleans, Louisiana, on October 18, 1939, to Robert Edward Lee Oswald, Sr. and Marguerite Frances Claverie. Robert Oswald was a distant cousin of Confederate general Robert E. Lee and served in the Marines during World War I. Robert died of a heart attack two months. Lee's elder brother Robert, Jr. was a former Marine. Through Marguerite's first marriage to Edward John Pic, Jr. Lee and Robert Jr. were the half-brothers of Air Force veteran John Edward Pic.
In 1944, Marguerite moved the family from New Orleans to Texas. Oswald entered the first grade in 1945 and over the next half-dozen years attended several different schools in the Dallas and Fort Worth areas through the sixth grade. Oswald took an IQ test in the fourth grade and scored 103; when Oswald was 12 in August 1952, his mother took him to New York City where they lived for a short time with Oswald's half-brother, John. Oswald and his mother were asked to leave after an argument in which Oswald struck his mother and threatened John's wife with a pocket knife. Oswald attended seventh grade in the Bronx, New York, but was truant, which led to a psychiatric assessment at a juvenile reformatory; the reformatory psychiatrist, Dr. Renatus Hartogs, described Oswald as immersed in a "vivid fantasy life, turning around the topics of omnipotence and power, through which tries to compensate for his present shortcomings and frustrations." Dr. Hartogs detected a "personality pattern disturbance with schizoid features and passive-aggressive tendencies" and recommended continued treatment.
In January 1954, Marguerite took Lee with her. At the time, there was a question pending before a New York judge as to whether Oswald should be removed from the care of his mother to finish his schooling, although Oswald's behavior appeared to improve during his last months in New York. Oswald completed the ninth grades in New Orleans, he quit school after one month. After leaving school, Oswald worked for several months as an office clerk and messenger in New Orleans. In July 1956, Oswald's mother moved the family to Fort Worth and Oswald re-enrolled in the 10th grade for the September session at Arlington Heights High School in Fort Worth. A few weeks in October, Oswald quit school at age 17 to join the Marines. By this point, he attended 12 schools. Though Oswald had trouble spelling in his youth and may have had a "reading-spelling disability", he read voraciously. By age 15, he considered himself a Marxist according to his diary: "I was looking for a key to my environment, I discovered socialist literature.
I had to dig for my books in the back dusty shelves of libraries." At 16 he wrote to the Socialist Party of America for information on their Young People's Socialist League, saying he had been studying socialist principles for "well over fifteen months." However, Edward Voebel, "whom the Warren Commission had established was Oswald's closest friend during his teenage years in New Orleans..... said that reports that Oswald was already'studying Communism' were a'lot of baloney.' " Voebel said that "Oswald read'paperback trash.'"As a teenager in 1955, Oswald attended Civil Air Patrol meetings in New Orleans. Fellow cadets recalled him attending C. A. P. Meetings "three or four" times, or "10 or 12 times" over a one- or two-month period. Oswald enlisted in the United States Marine Corps on October 24, 1956, just after his seventeenth birthday, he was underage and his brother Robert, Jr. was required to sign the forms as his legal guardian. Oswald named his mother and his half-brother John as beneficiaries.
Oswald wore his Marine Corps ring. John Pic testified to the Warren Commissi
In firearms terminology, an action is the mechanism of a breech-loading weapon that handles the ammunition or the method by which that mechanism works. Actions are technically not present on muzzleloaders, as all are single-shot weapons with a closed off breech. Instead, the ignition mechanism is referred to Actions can be categorized in several ways, including single action versus double action, break action versus bolt action, others; the term action can include short and magnum if it is in reference to the length of the rifle's receiver and the length of the bolt. The short action rifle can accommodate a cartridge length of 2.8 in or smaller. The long action rifle can accommodate a cartridge of 3.34 in, the magnum action rifle can accommodate cartridges of 3.6 in, or longer in length. The dropping block are actions wherein the breechblock lowers or "drops" into the receiver to open the breech actuated by an underlever. There are two principal types of dropping block: the falling block. In a tilting block or pivoting block action, the breechblock is hinged on a pin mounted at the rear.
When the lever is operated, the block tilts forward, exposing the chamber. The best-known pivoting block designs are the Peabody, the Peabody–Martini, Ballard actions; the original Peabody rifles, manufactured by the Providence Tool Company, used a manually cocked side-hammer. Swiss gunsmith Friedrich Martini developed a pivoting block action by modifying the Peabody, that incorporated a hammerless striker, cocked by the operating lever with the same single, efficient motion that pivoted the block; the 1871 Martini–Henry which replaced the "trapdoor" Snider–Enfield was the standard British Army rifle of the Victorian era, the Martini was a popular action for civilian rifles. Charles H. Ballard's self-cocking tilting-block action was produced by the Marlin Firearms Company from 1875, earned a superlative reputation among long-range "Creedmoor" target shooters. Surviving Marlin Ballards are today prized by collectors those mounted in the elaborate Swiss-style Schützen stocks of the day. A falling block action is a single-shot firearm action in which a solid metal breechblock slides vertically in grooves cut into the breech of the weapon and actuated by a lever.
Examples of firearms using the falling block action are the Sharps rifle and Ruger No. 1. In a rolling block action the breechblock takes the form of a part-cylinder, with a pivot pin through its axis; the operator rotates or "rolls" the block to close the breech. Rolling blocks are most associated with firearms made by Remington in the 19th century; the hinged block was the earliest metallic-cartridge breechloaders designed for general military issue began as conversions of muzzle-loading rifle-muskets. The upper rear portion of the barrel was filed or milled away and replaced by a hinged breechblock which opened upward to permit loading. An internal angled firing pin allowed the re-use of the rifle's existing side-hammer; the Allin action made by Springfield Arsenal in the US hinged forward. Whereas the British replaced the Snider with a dropping-block Peabody-style Martini action, the US Army felt the trapdoor action to be adequate and followed its muzzleloader conversions with the new-production Springfield Model 1873, the principal longarm of the Indian Wars and was still in service with some units in the Spanish–American War.
A break action is a type of firearm where the barrel are hinged and can be "broken open" to expose the breech. Multi-barrel break action firearms are subdivided into over-and-under or side-by-side configurations for two barrel configurations or "combination gun" when mixed rifle and shotgun barrels are used. Although bolt-action guns are associated with fixed or detachable box magazines, in fact the first general-issue military breechloader was a single-shot bolt action: the paper-cartridge Prussian needle gun of 1841. France countered in 1866 with its superior Chassepot rifle a paper-cartridge bolt action; the first metallic-cartridge bolt actions in general military service were the Berdan Type II introduced by Russia in 1870, the Mauser Model 1871, a modified Chassepot, the Gras rifle of 1874. Today most top-level smallbore match rifles are single-shot bolt actions. Single-shot bolt actions in.22 caliber were widely manufactured as inexpensive "boys' guns" in the earlier 20th century. The eccentric screw action first seen on the M1867 Werndl–Holub and on the Magnum Research Lone Eagle pistol, the breech closure is a rotating drum with the same axis, but offset from the bore.
When locked, a firing pin aligns with the primer and the breech is otherwise solid. When rotated open, a slot in the drum is exposed for feeding of a new round. Though first used on the Werndl-Holub, this action is known as a cannon breech due to its association with the French 75mm Model of 1897 cannon; the French M1897 was, based on William Hubbell's U. S. Patent 149,478; the Ferguson rifle: British Major Patrick Ferguson designed his rifle, considered to be the first military breechloader, in the 1770s. A plug-shaped breechblock was screw-threaded so that rotating the handle underneath would lower a
World War II
World War II known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from over 30 countries; the major participants threw their entire economic and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China, it included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, the only use of nuclear weapons in war. Japan, which aimed to dominate Asia and the Pacific, was at war with China by 1937, though neither side had declared war on the other. World War II is said to have begun on 1 September 1939, with the invasion of Poland by Germany and subsequent declarations of war on Germany by France and the United Kingdom.
From late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or controlled much of continental Europe, formed the Axis alliance with Italy and Japan. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union partitioned and annexed territories of their European neighbours, Finland and the Baltic states. Following the onset of campaigns in North Africa and East Africa, the fall of France in mid 1940, the war continued between the European Axis powers and the British Empire. War in the Balkans, the aerial Battle of Britain, the Blitz, the long Battle of the Atlantic followed. On 22 June 1941, the European Axis powers launched an invasion of the Soviet Union, opening the largest land theatre of war in history; this Eastern Front trapped most crucially the German Wehrmacht, into a war of attrition. In December 1941, Japan launched a surprise attack on the United States as well as European colonies in the Pacific. Following an immediate U. S. declaration of war against Japan, supported by one from Great Britain, the European Axis powers declared war on the U.
S. in solidarity with their Japanese ally. Rapid Japanese conquests over much of the Western Pacific ensued, perceived by many in Asia as liberation from Western dominance and resulting in the support of several armies from defeated territories; the Axis advance in the Pacific halted in 1942. Key setbacks in 1943, which included a series of German defeats on the Eastern Front, the Allied invasions of Sicily and Italy, Allied victories in the Pacific, cost the Axis its initiative and forced it into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained its territorial losses and turned toward Germany and its allies. During 1944 and 1945 the Japanese suffered major reverses in mainland Asia in Central China, South China and Burma, while the Allies crippled the Japanese Navy and captured key Western Pacific islands; the war in Europe concluded with an invasion of Germany by the Western Allies and the Soviet Union, culminating in the capture of Berlin by Soviet troops, the suicide of Adolf Hitler and the German unconditional surrender on 8 May 1945.
Following the Potsdam Declaration by the Allies on 26 July 1945 and the refusal of Japan to surrender under its terms, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August respectively. With an invasion of the Japanese archipelago imminent, the possibility of additional atomic bombings, the Soviet entry into the war against Japan and its invasion of Manchuria, Japan announced its intention to surrender on 15 August 1945, cementing total victory in Asia for the Allies. Tribunals were set up by fiat by the Allies and war crimes trials were conducted in the wake of the war both against the Germans and the Japanese. World War II changed the political social structure of the globe; the United Nations was established to foster international co-operation and prevent future conflicts. The Soviet Union and United States emerged as rival superpowers, setting the stage for the nearly half-century long Cold War. In the wake of European devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia.
Most countries whose industries had been damaged moved towards economic expansion. Political integration in Europe, emerged as an effort to end pre-war enmities and create a common identity; the start of the war in Europe is held to be 1 September 1939, beginning with the German invasion of Poland. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937, or the Japanese invasion of Manchuria on 19 September 1931. Others follow the British historian A. J. P. Taylor, who held that the Sino-Japanese War and war in Europe and its colonies occurred and the two wars merged in 1941; this article uses the conventional dating. Other starting dates sometimes used for World War II include the Italian invasion of Abyssinia on 3 October 1935; the British historian Antony Beevor views the beginning of World War II as the Battles of Khalkhin Gol fought between Japan and the fo
A cartridge is a type of pre-assembled firearm ammunition packaging a projectile, a propellant substance and an ignition device within a metallic, paper or plastic case, made to fit within the barrel chamber of a breechloading gun, for the practical purpose of convenient transportation and handling during shooting. Although in popular usage the term "bullet" is used to refer to a complete cartridge, it is used only to refer to the projectile. Cartridges can be categorized by the type of their primers — a small charge of an impact- or electric-sensitive chemical mixture, located at the center of the case head, inside the rim of the case base, in a sideway projection, shaped like a pin or a lip, or in a small nipple-like bulge at the case base. Military and commercial producers continue to pursue the goal of caseless ammunition; some artillery ammunition uses the same cartridge concept. In other cases, the artillery shell is separate from the propellant charge. A cartridge without a projectile is called a blank.
One, inert is called a dummy. One that failed to ignite and shoot off the projectile is called a dud, one that ignited but failed to sufficiently push the projectile out of the barrel is called a squib; the primary purpose is to be a handy all-in-one for a shot. In modern, automatic weapons, it provides the energy to move the parts of the gun which make it fire repeatedly. Many weapons were designed to make use of a available cartridge, or a new one with new qualities; the cartridge case seals a firing chamber in all directions excepting the bore. A firing pin ignites it; the primer compound deflagrates, it does not detonate. A jet of burning gas from the primer ignites the propellant. Gases from the burning powder expand the case to seal it against the chamber wall; these propellant gases push on the bullet base. In response to this pressure, the bullet will move in the path of least resistance, down the bore of the barrel. After the bullet leaves the barrel, the chamber pressure drops to atmospheric pressure.
The case, elastically expanded by chamber pressure, contracts slightly. This eases removal of the case from the chamber. To manufacture brass for cartidges, a sheet of brass is punched into disks; these disks go through a series of punches and dies and are annealed and washed before moving to the next series of dies. Making bullets involves simular type of maching as for making brass cases; the projectile can be made of anything. Lead is a material of choice because of high density, ductility; the propellant was long gunpowder, still in use, but superseded by better compositions, generically called Smokeless powder. Early primer was fine gunpowder poured into a pan or tube where it could be ignited by some external source of ignition such as a fuse or a spark. Modern primers are shock sensitive chemicals enclosed in a small capsule, ignited by percussion. In some instance ignition is electricity-primed, there may be no primer at all in such design; the case is made of brass because it is resistant to corrosion.
A brass case head can be work-hardened to withstand the high pressures of cartridges, allow for manipulation via extraction and ejection without tearing the metal. The neck and body portion of a brass case is annealed to make the case ductile enough to allow reforming so that it can be reloaded many times. Steel is used in some plinking ammunition, as well as in some military ammunition. Steel is less expensive than brass. Military forces consider small arms cartridge cases to be disposable, one-time-use devices. However, case weight affects how much ammunition a soldier can carry, so the lighter steel cases do have a military advantage. Conversely, steel is more susceptible to contamination and damage so all such cases are varnished or otherwise sealed against the elements. One downside caused by the increased strength of steel in the neck of these cases is that propellant gas can blow back past the neck and into the chamber. Constituents of these gases condense on the chamber wall; this solid propellant residue can make extraction of fired cases difficult.
This is less of a problem for small arms of the former Warsaw Pact nations, which were designed with much larger chamber tolerances than NATO weapons. Aluminum cased; these are not reloaded as aluminum fatigues during firing and resizing. Some calibers have non-standard primer sizes to discourage reloaders from attempting to reuse these cases. Plastic cases are used in shotgun shells and some manufacturers offer polymer centerfire cartridges. Paper had been used in the earliest cartridges. Critical cartridge specifications include neck size, bullet weight and caliber, maximum pressure, overall length, case body diameter and taper, shoulder design, rim type, etc. Ever