1.
Hollow-point bullet
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It is also used for controlled penetration, where over-penetration could cause collateral damage. Both of these goals are meant to maximize stopping power, jacketed hollow points or plated hollow points are covered in a coating of harder metal to increase bullet strength and to prevent fouling the barrel with lead stripped from the bullet. Plastic-tipped bullets are a type of bullet meant to confer the aerodynamic advantage of the spitzer bullet and this process is commonly referred to as mushrooming, because the resulting shape, a widened, rounded nose on top of a cylindrical base, typically resembles a mushroom. The greater frontal surface area of the expanded bullet limits its depth of penetration into the target and this jacket provides additional strength to the bullet, and can help prevent it from leaving deposits of lead inside the bore. In controlled expansion bullets, the jacket and other design characteristics help to prevent the bullet from breaking apart. For bullets designed for shooting, some such as the Sierra Matchking incorporate a cavity in the nose. Match or target hollow-point bullets are designed for target use. A hollow-point boat-tail bullet is a match-grade bullet design that uses the concept of a tail to give it a lower drag coefficient. Only the base of the bullet has a boat tail-like shape – the meplat is still pointed, some hollow-point boat-tail bullets with longer, more aerodynamic profiles are known as very-low-drag bullets. Terminal ballistics testing of hollow point bullets is generally performed in ballistic gelatin, or some other medium intended to simulate tissue, Test results are generally given in terms of expanded diameter, penetration depth, and weight retention. How these factors are interpreted depends on the use of the bullet. Solid lead bullets, when cast from an alloy, will often deform. This, combined with the velocity and penetration attainable with muzzleloading firearms. The first hollow-point bullets were marketed in the late 19th century as express bullets, in addition to providing increased velocities, the hollow also turned out to provide significant expansion, especially when the bullets were cast in a soft lead alloy. Originally intended for rifles, the popular. 32-20. 38-40, with the advent of smokeless powder, velocities increased, and bullets got smaller, faster, and lighter. These new bullets needed to be jacketed to handle the conditions of firing, the new full metal jacket bullets tended to penetrate straight through a target and produce little damage. This led to the development of the soft point bullet and later jacketed hollow-point bullets at the British arsenal in Dum Dum, designs included the.303 Mk III, IV & V and the.455 Mk III Manstopper cartridges. Although such bullet designs were quickly outlawed for use in warfare, in modern ammunition, the use of hollow points is primarily limited to handgun ammunition, which tends to operate at much lower velocities than rifle ammunition
2.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
3.
Rifling
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In firearms, rifling consists of helical grooves in the internal surface of a guns barrel, which impart a spin to a projectile around its long axis. This spin serves to stabilize the projectile, improving its aerodynamic stability. Rifling is often described by its twist rate, which indicates the distance the rifling takes to complete one revolution, such as 1 turn in 10 inches. A shorter distance indicates a faster twist, meaning that for a given velocity the projectile will be rotating at a spin rate. Barrels intended for long, small-diameter bullets, such as the ultra-low-drag, 80-grain 0.223 inch bullets, extremely long projectiles such as flechettes may require high twist rates, these projectiles must be inherently stable, and are often fired from a smoothbore barrel. Muskets were smoothbore, large caliber weapons using ball-shaped ammunition fired at low velocity. Due to the high cost and great difficulty of manufacturing, and the need to load readily from the muzzle. Consequently, on firing the ball bounced off the sides of the barrel when fired, barrel rifling was invented in Augsburg, Germany in 1498. In 1520 August Kotter, an armourer of Nuremberg, Germany improved upon this work, though true rifling dates from the mid-16th century, it did not become commonplace until the nineteenth century. The most successful weapons using rifling with black powder were breech loaders such as the Queen Anne pistol, the grooves most commonly used in modern rifling have fairly sharp edges. More recently, polygonal rifling, a throwback to the earliest types of rifling, has become popular, polygonal barrels tend to have longer service lives because the reduction of the sharp edges of the land reduces erosion of the barrel. Supporters of polygonal rifling also claim higher velocities and greater accuracy, polygonal rifling is currently seen on pistols from CZ, Heckler & Koch, Glock, Tanfoglio, and Kahr Arms, as well as the Desert Eagle. Such guns have achieved significant increases in velocity and range. Examples include the South African G5 and the German PzH2000, gain-twist rifling begins with very little change in the projectiles angular momentum during the first few inches of bullet travel after ignition during the transition from chamber to throat. This enables the bullet to remain undisturbed and trued to the case mouth. After engaging the rifling the bullet is progressively subjected to accelerated angular momentum as burning powder propels it down the barrel. By only gradually increasing the rate, torque is spread along a much longer section of barrel. Gain-twist rifling was used as early as the American Civil War, colt Army and Navy revolvers both employed gain-twist rifling
4.
.30-06 Springfield
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The.30 refers to the caliber of the bullet, and the 06 refers to the year the cartridge was adopted—1906. It replaced the. 30-03, 6mm Lee Navy, and. 30-40 Krag cartridges and it remains a very popular sporting round, with ammunition produced by all major manufacturers. In the early 1890s, the U. S. military adopted the smokeless powder. 30-40 Krag rimmed cartridge, the 1894 version of that cartridge used a 220-grain round-nose bullet. Around 1901, the U. S. started developing an experimental rimless cartridge for a Mauser action with box magazine and that led to the 1903. 30-03 rimless service round that used the same 220-grain round-nose bullet as the Krag. The. 30-03 achieved a velocity of 2,300 ft/s. Consequently, the round-nosed U. S. 30-03 service cartridge was falling behind. For these reasons, the U. S. military developed a new, lighter, cartridge in 1906, the cartridge was loaded with Military Rifle 21 propellant, and its maximum range was claimed to be 4,700 yd. The M1903 Springfield rifle, which had been introduced alongside the. 30-03 cartridge, was modified to accept the new. 30-06 Springfield cartridge. Modifications to the rifle included shortening the barrel at its breech and resizing the chamber, other changes to the rifle included elimination of the troublesome rod bayonet of the earlier Springfield rifles. The M1906 maximum range was originally overstated, when the M1906 cartridge was developed, the range tests had been done to only 1,800 yards, distances beyond that were estimated, but the estimate for extreme range was wrong by almost 40 percent. The range discrepancy became evident during World War I, before the widespread employment of light mortars and artillery, long-range machine gun barrage or indirect fires were considered important in U. S. infantry tactics. When the US entered World War I, it did not have machine guns, so it acquired British. When those weapons were replaced with US machine guns firing the M1906 round. Firing tests performed around 1918 at Borden Brook Reservoir, Miami, patrone was inroduced in 1914 and used a 197. 5-grain s. S. - schweres Spitzgeschoß boat-tail bullet which had a maximum range of approximately 5,140 yd. Its maximum range was approximately 5,500 yd. Additionally, wartime surplus totaled over 2 billion rounds of ammunition. Army regulations called for training use of the oldest ammunition first, as a result, the older. 30-06 ammunition was expended for training, stocks of.30 M1 Ball ammunition were allowed to slowly grow until all of the older M1906 ammunition had been fired. By 1936, it was discovered that the range of the.30 M1 Ball ammunition with its boat-tailed spitzer bullets was beyond the safety limitations of many ranges. An emergency order was made to manufacture quantities of ammunition that matched the ballistics of the earlier M1906 cartridge as soon as possible
5.
Action (firearms)
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In firearms terminology, an action is the mechanism that handles the ammunition or the method by which that mechanism works. Breech-loading weapons have actions, actions are not present on muzzleloaders. The mechanism that fires a muzzle-loader is called the lock, actions can be categorized in several ways, including single action versus double action, break action versus bolt action, and others. The term action can also short, long, and magnum if it is in reference to the length of the rifle’s receiver. The short action rifle usually can accommodate a cartridge length of 2.8 in or smaller, the long action rifle can accommodate a cartridge of 3.34 in, and the magnum action rifle can accommodate cartridges of 3.6 in, or longer in length. Manual operation is a term describing any type of firearm action that is loaded one shot at a time by the user rather than automatically. For example, break action is a form of operation using a simple hinge mechanism that is manually unlatched by the operator. These are actions wherein the breechblock lowers or drops into the receiver to open the breech, there are two principal types of dropping block, the tilting block and the falling block. In a tilting or pivoting block action, the breechblock is hinged on a pin mounted at the rear, when the lever is operated, the block tilts down and forward, exposing the chamber. The best-known pivoting block designs are the Peabody, the Peabody–Martini, the original Peabody rifles, manufactured by the Providence Tool Company, used a manually cocked side-hammer. The 1871 Martini–Henry which replaced the trapdoor Snider–Enfield was the standard British Army rifle of the later Victorian era, charles H. Ballards self-cocking tilting-block action was produced by the Marlin Firearms Company from 1875, and earned a superlative reputation among long-range Creedmoor target shooters. Surviving Marlin Ballards are today highly prized by collectors, especially those mounted in the elaborate Swiss-style Schützen stocks of the day. A falling-block action is a firearm action in which a solid metal breechblock slides vertically in grooves cut into the breech of the weapon. Examples of firearms using the falling block action are the Sharps rifle, 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 open and close the breech, it is a simple, rugged, a break action is a type of firearm where the barrel are hinged and can be broken open to expose the breech. The earliest metallic-cartridge breechloaders designed for military issue began as conversions of muzzle-loading rifle-muskets. The upper rear portion of the barrel was filed or milled away, an internal angled firing pin allowed the re-use of the rifles existing side-hammer. The Allin action made by Springfield Arsenal in the US hinged forward, france countered in 1866 with its superior Chassepot rifle, also a paper-cartridge bolt action
6.
Cartridge (firearms)
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Military and commercial producers continue to pursue the goal of caseless ammunition. A cartridge without a bullet is called a blank, One that is completely inert is called a dummy. Some artillery ammunition uses the same concept as found in small arms. In other cases, the shell is separate from the propellant charge. In popular use, the bullet is often misused to refer to a complete cartridge. The cartridge case seals a firing chamber in all directions excepting the bore, a firing pin strikes the primer and 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 pressurize and expand the case to seal it against the chamber wall and these propellant gases push on the bullet base. In response to pressure, the bullet will move in the path of least resistance which is down the bore of the barrel. After the bullet leaves the barrel, the pressure drops to atmospheric pressure. The case, which had been expanded by chamber pressure. This eases removal of the case from the chamber, brass is a commonly used case material because it is resistant to corrosion. A brass case head can be work-hardened to withstand the pressures of cartridges. The neck and body portion of a case is easily 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 military ammunition. Steel is less expensive than brass, but it is not feasible to reload, Military forces typically consider small arms cartridge cases to be disposable, one-time-use devices. However, case weight affects how much ammunition a soldier can carry, 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 strength of steel in the neck of these cases is that propellant gas can blow back past the neck
7.
Bullet
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The word bullet is a firearm term. A bullet is a projectile expelled from the barrel of a firearm, the term is from Middle French and originated as the diminutive of the word boulle which means small ball. Bullets are made of a variety of materials and they are available singly as they would be used in muzzle loading and cap and ball firearms, as part of a paper cartridge, and much more commonly as a component of metallic cartridges. Bullets are made in a numbers of styles and constructions depending on how they will be used. Many bullets have specialized functions, such as hunting, target shooting, training, defense, a bullet is not a cartridge. In paper and metallic cartridges a bullet is one component of the cartridge, bullet sizes are expressed by their weight and diameter in both English and Metric measurement systems. For example.22 caliber 55 grain bullets or 5. 56mm 55 grain bullets are the same caliber, the word bullet is often used colloquially to refer to a cartridge, which is a combination of the bullet, paper or metallic case/shell, powder, and primer. This use of bullet, when cartridge is intended, leads to confusion when the components of a cartridge are discussed or intended, the bullets used in many cartridges are fired at a muzzle velocity faster than the speed of sound. Meaning they are supersonic and thus can travel a substantial distance, bullet speed through air depends on a number of factors such as barometric pressure, humidity, air temperature, and wind speed. Subsonic cartridges fire bullets slower than the speed of sound and so there is no sonic crack and this means that a subsonic cartridge such as.45 ACP can be effectively suppressed to be substantially quieter than a supersonic cartridge such as the.223 Remington. Bullets do not normally contain explosives, but damage the target by impact. The first use of gunpowder in Europe was recorded in 1247 and it had been used in China for hundreds of years. Later in 1364 hand cannon appeared, early projectiles were made of stone. Stone was used in cannon and hand cannon, in cannon it was eventually found that stone would not penetrate stone fortifications which gave rise to the use of heavier metals for the round projectiles. Hand cannon projectiles developed in a similar following the failure of stone from siege cannon. The first recorded instance of a ball from a hand cannon penetrating armor occurred in 1425. In this photograph of shot retrieved from the wreck of the Mary Rose which was sunk in 1545, the round shot are clearly of different sizes and some are stone while others are cast iron. The development of the hand culverin and matchlock arquebus brought about the use of cast lead balls as projectiles, bullet is derived from the French word boulette, which roughly means little ball
8.
.223 Remington
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The.223 Remington is a rifle cartridge. The name is pronounced either two-twenty-three or two-two-three Remington. It is commercially loaded with 0.224 inch diameter jacketed bullets, with weights ranging from 40 to 85 grains, a 90 gr Sierra Matchking bullet is available for reloaders. The.223 Rem was first offered to the sporting market in December 1963 in the Remington 760 rifle. In 1964 the.223 Rem cartridge was adopted for use in the Colt M16 rifle which became a standard rifle of the U. S. Army. The military version of the uses a 55 gr full metal jacket boattail design and was designated M193. In 1980 NATO modified the.223 Remington into a new design which is designated 5. 56×45mm NATO type SS109, the cartridge and rifle were developed as one unit by Fairchild Industries, Remington Arms, and several engineers working toward a goal developed by U. S. Early development work begins in 1957, a project to create a Small Caliber High Velocity firearm is created. Eugene Stoner of Armalite is invited to scale down the AR-10 design, Winchester is also invited to participate. It was then known as the.224 Springfield, concurrently with the SCHV project Springfield armory is developing a 7.62 mm rifle. Harvey is ordered to cease all work on the SCHV to avoid any competition of resources, eugene Stoner of Armalite had been advised to produce a scaled down version of the 7.62 mm AR-10 design. In May 1957 Stoner gives a live demonstration of the prototype of the AR-15 for General Wyman. As a result, CONARC orders rifles to test, Stoner and Sierra Bullets Frank Snow begin work on the.222 Remington cartridge. Using a ballistic calculator they determine that a 55 grain bullet would have to be fired at 3, robert Hutton starts development of a powder load to reach the 3,300 fps goal. He uses DuPont IMR4198, IMR3031 and an Olin Powder to work up loads, testing is done with a Remington 722 rifle with a 22 Apex Barrel. During a public demonstration the round penetrates the US steel helmet as required. But testing shows chamber pressures to be excessively high, Stoner contacts both Winchester and Remington about increasing the case capacity. Remington creates a larger cartridge which is called the.222 Special which is loaded with DuPont IMR4475 powder,1958, During parallel testing of the T44E4 and the AR-15 the T44E4 experiences 16 failures per 1,000 rounds fired compared to 6.1 for the AR-15
9.
Grain (unit)
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A grain is a unit of measurement of mass, and, for the troy grain, equal to exactly 7001647989100000000♠64.79891 milligrams. It is nominally based upon the mass of a seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat, rather, expressions such as thirty-two grains of wheat, taken from the middle of the ear appear to have been ritualistic formulas, essentially the premodern equivalent of legal boilerplate. Another book states that Captain Henry Kater, of the British Standards Commission, the grain was the legal foundation of traditional English weight systems, and is the only unit that is equal throughout the troy, avoirdupois, and apothecaries systems of mass. The unit was based on the weight of a grain of barley. The fundamental unit of the pre-1527 English weight system known as Tower weights, was a different sort of known as the wheat grain. The Tower wheat grain was defined as exactly 45⁄64 of a troy grain.79891 milligrams, 7000100000000000000♠1 gram is approximately 7001154323600000000♠15.43236 grains. The unit formerly used by jewellers to measure pearls, diamonds, or other stones, called the jewellers grain or pearl grain, is equal to 1⁄4 of a carat. The grain was also the name of a traditional French unit equal to 6995531150000000000♠53.115 mg. In both British Imperial and U. S. customary units, there are precisely 7,000 grains per avoirdupois pound, the grain is commonly used to measure the mass of bullets and propellants. The term also refers to a particle of gunpowder, the size of which varies according to requirements. In archery, the grain is the unit used to weigh arrows. In dentistry, gold foil, used as a material to restore teeth, is measured in grains, in North America, the hardness of water is often measured in grains per US gallon of calcium carbonate equivalents. Otherwise, water hardness is measured in the metric unit parts per million, one grain per US gallon is approximately 6995171000000000000♠17.1 ppm. Soft water contains 1–4 gpg of calcium carbonate equivalents, while hard water contains 11–20 gpg, though no longer recommended, grains are still used occasionally in medicine as part of the apothecaries system, especially in prescriptions for older medicines such as aspirin or phenobarbital. For example, the dosage of a standard 6996325000000000000♠325 mg tablet of aspirin is sometimes given as 7000500000000000000♠5 grains, in that example the grain is approximated to 6995650000000000000♠65 mg, though the grain can also be approximated to 6995600000000000000♠60 mg, depending on the medication and manufacturer. The apothecaries system has its own system of notation, in which the symbol or abbreviation is followed by the quantity in lower case Roman numerals. For amounts less than one, the quantity is written as a fraction, or for one half, therefore, a prescription for tablets containing 325 mg of aspirin and 30 mg of codeine can be written ASA gr
10.
7mm Remington Magnum
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The 7mm Remington Magnum rifle cartridge was introduced as a commercially available round in 1962, along with the new Remington Model 700 bolt-action rifle. It is a member of the belted magnum family that is derived from the venerable.375 H&H Magnum. Improved cartridge extraction reliability is desirable while hunting game, which would be of concern when needing a fast follow up shot. On its introduction, the 7mm Remington Magnum substantially usurped the market held by the.264 Winchester Magnum. Remington has recently offered Managed Recoil ammunition for achieving reduced recoil when shooting and for generating less meat damage when hunting smaller game. The 7mm Remington Magnum offers ballistics better than the. 30-06 Springfield with bullet weights of 175 grains and less and it is arguable that the 7mm Remington Magnum offers marginally better ballistics with 175 grain bullets, the heaviest bullet commonly used in the caliber. The. 30-06 Springfield can, however, be loaded with heavier bullets up to 220 grains, the 7mm Remington Magnum has 5.31 ml H2O cartridge case capacity. Americans would define the angle at alpha/2 =25 degrees. The common rifling twist rate for this cartridge is 241 mm,6 grooves, Ø lands =7.04 mm, Ø grooves =7.21 mm, land width =2.79 mm and the primer type is large rifle magnum. Rulings the 7mm Remington Magnum case can handle up to 430.00 MPa Pmax piezo pressure, regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C. I. P. pressure to certify for sale to consumers. This means that 7mm Remington Magnum chambered arms in C. I. P, regulated countries are currently proof tested at 537.50 MPa PE piezo pressure. The SAAMI Maximum Average Pressure for this cartridge is 61,000 psi piezo pressure, the rebated rim bottlenecked centerfire short magnum 7mm Winchester Short Magnum cartridge introduced in 2001 is probably the closest ballistic twin of the 7mm Remington Magnum. The 7mm Winchester Short Magnum is considerably shorter and fatter and has a shoulder angle. This makes the 7mm Remington Magnum case with its 6.89 mm long neck better suited for loading long heavier bullets, the 7mm Remington Short Action Ultra Magnum is considerably shorter and fatter and has a steeper shoulder angle and a longer neck than the 7mm Remington Magnum. This makes the 7mm Remington Short Action Ultra Magnum better suited for loading long heavier bullets and it has also been chambered in sniper rifles as the US Secret Service counter-sniper team has deployed this cartridge in urban areas. Popular online gun author Chuck Hawks calls the 7mm Remington one of the great all-around rifle cartridges, thus one would do well to use a premium bullet of some sort, for instance a bonded bullet
11.
.300 Winchester Magnum
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The.300 Winchester Magnum is a belted, bottlenecked magnum rifle cartridge that was introduced by Winchester Repeating Arms Company in 1963. The.300 Winchester Magnum is a cartridge designed to fit in a standard rifle actions. It is based on the.375 H&H Magnum, which has blown out, shortened. The.300 Winchester is extremely versatile and has been adopted by a range of users including hunters, target shooters, military units. It is a selection for hunting moose, elk. Military and law enforcement departments adopted the cartridge for long range sniping, as a testament to its accuracy, since its introduction it has gone on to win several 1, 000-yard competitions. Prior to the design of the.300 Winchester Magnum there were several cartridges that provided what could be best described as a level of energy. The heritage of.30 caliber magnums can be traced back to the.30 Newton in 1913, beginning with the.270 Weatherby Magnum in 1943, Roy Weatherby introduced a line of cartridges based on a standard length magnum case. This was accomplished by taking the.30 Super Belted Rimless H&H case and having it blown out and shortened so that it could be cycled through a standard length bolt-action rifle. Then in 1944 he designed the.300 Weatherby Magnum, which essentially was a version of the.30 Super Belted Rimless H&H. The Weatherby’s standard length magnum case was soon noticed, in 1958 Winchester introduced three cartridges – the.264 Winchester Magnum.338 Winchester Magnum and the.458 Winchester Magnum, all based on the shortened and blown out.375 H&H Magnum case. The popular.30 caliber’s omission from that lineup was not missed, the.300 Winchester Magnum was introduced in 1963 by Winchester for use in the Model 70 rifle. The introduction of the.300 Winchester Magnum was not unforeseen, rather, its introduction was anticlimactic. Winchester developed the.300 Winchester Magnum by taking the.338 Winchester Magnum, which was introduced in 1958 and this caused the cartridge to have a neck shorter than the diameter of the bullet. There has been speculation that if the cartridge was released earlier. Since its introduction the cartridge has remained extremely popular, the.300 Winchester Magnums high availability in popular rifles such as Winchesters Model 70 and Remington Model 700 made the cartridge a popular choice among the shooting public. Although the.300 H&H Magnum. 30-338 Winchester Magnum and the.308 Norma Magnum had a start on the.300 Winchester Magnum these cartridges soon faded into obsolescence. Only the.300 Winchester Magnum was to survive as a readily available cartridge, other cartridges, while available, are more expensive
