1.
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
2.
Gun barrel
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A gun barrel is a part of firearms and artillery pieces. The hollow interior of the barrel is called the bore, a gun barrel must be able to hold in the expanding gas produced by the propellants to ensure that optimum muzzle velocity is attained by the projectile as it is being pushed out by the expanding gas. Modern small arms barrels are made of known and tested to withstand the pressures involved. Artillery pieces are made by various techniques providing reliably sufficient strength, early firearms were muzzle-loading, with powder, and then shot loaded from the muzzle, capable of only a low rate of fire. During the 19th century effective mechanical locks were invented that sealed a breech-loading weapon against the escape of propellant gases, the early Chinese, the inventors of gunpowder, used bamboo, a naturally tubular stalk, as the first barrels in gunpowder projectile weapons. Early European guns were made of iron, usually with several strengthening bands of the metal wrapped around circular wrought iron rings. The Chinese were the first to master cast-iron cannon barrels, early cannon barrels were very thick for their caliber. Bore evacuator Bore snake Cannon Muzzle Polygonal rifling Rifling Slug barrel Smoothbore
3.
Suppressor
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Suppressors are typically constructed of a metal cylinder with internal mechanisms to reduce the sound of firing by slowing the escaping propellant gas. In most countries, silencers are regulated by legislation to varying degrees. While some have allowed for sporting use of silencers, other governments have opted to ban them from civilian use, American inventor Hiram Percy Maxim, the son of Maxim gun inventor Hiram Stevens Maxim, is usually credited with inventing and selling the first commercially successful models circa 1902. Maxim gave his device the trademarked name Maxim Silencer, and they were advertised in sporting goods magazines. Former president of the United States Theodore Roosevelt was known to purchase and use Maxim Silencers, suppressors were regularly used by agents of the United States Office of Strategic Services, who favored the newly designed High Standard HDM.22 Long Rifle pistol during World War II. OSS Director William Joseph Wild Bill Donovan demonstrated the pistol for President Franklin D. Roosevelt at the White House, according to OSS research chief Stanley Lovell, Donovan was waved into the Oval Office, where Roosevelt was dictating a letter. The British SOE Welrod pistol with a suppressor was also used by the American OSS on clandestine operations in Nazi occupied Europe during the Second World War. Both the United States Department of Justice and the ATF refer to suppressors as silencers, additionally, Hiram Percy Maxim marketed them as Maxim Silencers. The earliest use of the suppressor to refer to firearm noise reduction is in US Patent 4530417. When a firearm is discharged, there are three ways sound is produced, part of it can be managed, however, some of it is beyond the ability of the operator or manufacturers to eliminate. While subsonic ammunition can negate the sonic boom, mechanical noise can be mitigated but is impossible to eliminate. For these reasons, it is difficult to completely silence any firearm, some revolvers have technical features that enable suppression and include the Russian Nagant M1895 and OTs-38 revolvers, and the S&W QSPR. Muzzle blast generated by discharge is proportional to the amount of propellent contained within the cartridge. Therefore, the greater the case capacity the larger muzzle blast, a gunshot will almost always be louder than the sound of the action cycling of an auto-loading firearm. Paulson, a renowned firearms specialist, claimed to have encountered an integrally suppressed.22 LR that had such a quiet report, properly evaluating the sound generated by a firearm can only be done using a decibel meter in conjunction with a frequency spectrum analyser during live tests. The suppressor is typically a metal tube manufactured from steel, aluminium, or titanium. This device, typically cylindrical in shape, attaches to the muzzle of a pistol, submachine gun, some can-type suppressors, may be detached by the user and attached to a different firearm. Another type is the integral suppressor, which consists of an expansion chamber or chambers surrounding the barrel
4.
.45 ACP
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The.45 ACP, or.45 Auto is a handgun cartridge designed by John Browning in 1905, for use in his prototype Colt semi-automatic pistol. After successful military trials it was adopted along with the Browning.45 Colt handgun as the.45 M1911 cartridge, the handgun was designated M1911 handgun. The U. S. Cavalry had been buying and testing various handguns in the late 1890s, the.45 Colt Single Action Army had largely been replaced, even by some double-action versions of the same caliber. The Army had fielded some double-action revolvers in.38 Long Colt and they determined the.38 caliber round was significantly less effective than the.45 Colt against determined opponents such as the Moro juramentado warriors encountered in the Moro Rebellion. This experience, and the Thompson–LaGarde Tests of 1904 led the Army and they noted, however, training was critical to make sure a soldier could score a hit in a vulnerable part of the body. The result from Colt was the Model 1905 and the new.45 ACP cartridge. The resulting. 45-caliber cartridge, named the.45 ACP, was similar in performance to the.45 Schofield cartridge, by 1906, bids from six makers were submitted, among them Brownings design, submitted by Colt. Only DWM, Savage, and Colt made the first cut, DWM, which submitted two Parabellum P08s chambered in.45 ACP, withdrew from testing after the first round of tests, for unspecified reasons. In the second round of evaluations in 1910, the Colt design passed the testing with no failures. The Colt pistol was adopted as the Model 1911, the cartridge/pistol combination was quite successful but not satisfactory for U. S. military purposes. The very first production, at Frankford Arsenal, was marked F A811, the cartridge was designed by John Browning for Colt, but the most influential person in selecting the cartridge was Army Ordnance member Gen. John T. Thompson. Thompson insisted on a real man stopper pistol, following the showing of the Armys.38 Long Colt pistols during the Philippine–American War. The.45 ACP has 1.62 ml cartridge case capacity.45 ACP maximum C. I. P. The common rifling twist rate for this cartridge is 406 mm,6 grooves, Ø lands =11.23 mm, Ø grooves =11.43 mm, land width =3.73 mm and the primer type is large pistol. The cartridge headspaces on the mouth of the case at the L3 datum reference, according to Commission Internationale Permanente pour lEpreuve des Armes à Feu Portatives rulings, the.45 ACP cartridge case can handle up to 131.000 MPa Pmax piezo pressure. In CIP-regulated countries every pistol cartridge combination has to be proofed at 130% of this maximum CIP pressure to certify for sale to consumers and this means that.45 ACP chambered arms in C. I. P. Regulated countries are proof tested at 170.30 MPa PE piezo pressure. The SAAMI pressure limit for the.45 ACP is set at 21,000 psi piezo pressure, while the SAAMI pressure limit for the.45 ACP +P is set at 23,000 psi, piezo pressure
5.
Thompson/Center Arms
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Thompson/Center Arms is an American firearms company based in Springfield, Massachusetts. The company is best known for its line of interchangeable-barrel, single-shot pistols, Thompson/Center also manufactures muzzle-loading rifles and is credited with creating the resurgence of their use in the 1970s. In the 1960s, Warren Center developed an unusual break-action, single-shot pistol that later known as the Contender in his basement workshop. Meanwhile, the K. W. Thompson Tool Company had been searching for a product to manufacture year-round, in 1965, Warren Center joined the K. W. Thompson Tool Company, and together, they announced Warren Centers Contender pistol in 1967. As K. W. Thompson Tool began marketing Centers Contender pistol, then, in 1970, Thompson/Center created the modern black powder industry, introducing Warren Centers Hawken-styled black powder muzzle-loader rifle. On January 4,2007, Thompson/Center was purchased by Smith & Wesson, on December 8,2010, Smith & Wesson announced that the original Rochester, New Hampshire plant would be closed and manufacturing was transferred to Springfield, Massachusetts. Thompson/Centers success came with the emergence of long range hunting, target shooting. Their break-action, single-shot design brought rifle-like accuracy and power in a handgun, the Contender, first introduced in 1967, is a break-action, single-shot pistol or rifle with a number of unique features. The first unique feature is the way the barrel is attached to the frame, by removing the fore-end, a large hinge pin is exposed, by pushing this hinge pin out, the barrel can be removed. Since the sights and extractor remain attached to the barrel in the Contender design, a barrel of another caliber can be installed and pinned in place, the fore-end replaced, and the pistol is ready to shoot with a different barrel and pre-aligned sights. This allowed easy changes of calibers, sights, and barrel lengths, the Encore was released in 1983. The Encore uses a different trigger mechanism, designed to be stronger than the original Contenders, the Encore uses a considerably larger and stronger frame than the Contender, and accordingly, is found in over 86 cartridges - ranging from.22 Hornet to the huge.416 Rigby. There has even been one pistol-length stainless barrel made in.600 Nitro Express, the Encore barrel list also includes shotgun barrels in 28,20, and 12 gauge, and muzzleloading barrels in.45.50 caliber, and 12 gauge using #209 shotgun primers. In 2007, Encore rimfire barrels became available in 22 LR and 17 HMR, an upgraded T/C Encore is called the Pro Hunter which generally includes stocks with rubber Flex Tech inserts and are stainless or carbon steel with weather shielding. There are other differences among the rifles including the breech plug on muzzleloader versions. The original Contender, now known as the generation one Contender, was replaced by the G2 Contender soon after the Encore came out, the G2 Contender is essentially dimensionally the same as the original Contender, but uses an Encore style trigger group. Unlike the original Contender, dry-firing of the G2 Contender is possible only in the center hammer position, also, unlike the original Contender, the break-action does not need to be opened/closed to practice dry-firing, provided the hammer is lowered between dry firing shots. The adjustability of G2 Contender triggers is also different from the original G1 Contender
6.
Firearm
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A firearm is a portable gun - a barreled weapon that launches one or more projectiles, often driven by the action of an explosive force. The first primitive firearms originated in 13th-century China when the fire lance was combined with projectiles. The technology gradually spread through the rest of East Asia, South Asia, older firearms typically used black powder as a propellant, but modern firearms use smokeless powder or other propellants. Most modern firearms have rifled barrels to impart spin to the projectile for improved flight stability, modern firearms can be described by their caliber or in the case of shotguns their gauge, by the type of action employed together with the usual means of deportment. The word firearms usually is used in a sense restricted to small arms, shooters aim firearms at their targets with hand-eye co-ordination, using either iron sights or optical sights. The accurate range of pistols generally does not exceed 100 yards, while most rifles are accurate to 550 yards using iron sights, some purpose-built sniper rifles are accurate to ranges of more than 2,200 yards. The smallest of all firearms is the handgun, there are three common types of handguns, single-shot pistols, revolvers, and semi-automatic pistols. Revolvers have a number of firing chambers or charge holes in a revolving cylinder, semi-automatic pistols have a single fixed firing chamber machined into the rear of the barrel, and a magazine so they can be used to fire more than one round. Each press of the fires a cartridge, using the energy of the cartridge to activate the mechanism so that the next cartridge may be fired immediately. This is opposed to double-action revolvers which accomplish the end using a mechanical action linked to the trigger pull. Prior to the 19th century, virtually all handguns were single-shot muzzleloaders, with the invention of the revolver in 1818, handguns capable of holding multiple rounds became popular. Certain designs of auto-loading pistol appeared beginning in the 1870s and had largely supplanted revolvers in military applications by the end of World War I. By the end of the 20th century, most handguns carried regularly by military, police and civilians were semi-automatic, both designs are common among civilian gun owners, depending on the owners intention. A long gun is any firearm that is larger than a handgun and is designed to be held. Early long arms, from the Renaissance up to the century, were generally smoothbore firearms that fired one or more ball shot. Most modern long guns are either rifles or shotguns, both are the successors of the musket, diverging from their parent weapon in distinct ways. A rifle is so named for the spiral fluting machined into the surface of its barrel. Shotguns are predominantly smoothbore firearms designed to fire a number of shot, shotguns are also capable of firing single slugs, or specialty rounds such as bean bags, tear gas or breaching rounds
7.
Colt AR-15
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The Colt AR-15 is a lightweight,5. 56×45mm, magazine-fed, air-cooled semi-automatic, gas-operated rifle with a rotating bolt. It was designed to be manufactured with the use of aluminum alloys. Introduced in 1964, Colt has made many different types of AR-15 rifle and carbine models, including the AR-15, AR-15A2, AR-15A3, Sporter, HBAR, Government, Target, Match and it is based on the ArmaLite AR-15 rifle, a select-fire weapon intended for military sales. In 1959, ArmaLite sold the design to Colt due to financial difficulties, after some modifications, the rifle eventually became the United States military M16 rifle. Shortly thereafter, Colt began to make semi-automatic versions for civilian sales, the term AR-15 is a Colt registered trademark, which they use to denote only the semi-automatic rifle versions available for civilian and law enforcement sales. The term AR-15 signifies Armalite rifle, design 15, other manufacturers make AR-15 clones and variants marketed under separate designations, although these are frequently referred to as AR-15s. This article discusses the semiautomatic version manufactured by Colt, the Colt AR-15 is based on the 5.56 mm ArmaLite AR-15 rifle, which is a smaller lighter version of the 7.62 mm ArmaLite AR-10. Both of these rifles were designed by Eugene Stoner, Robert Fremont, in 1959, ArmaLite sold its rights to the AR-10 and AR-15 to Colt. After a Far East tour, Colt made its first sale of Colt made ArmaLite AR-15 rifles to Malaya on September 30,1959, Colt manufactured their first batch of 300 select-fire Colt ArmaLite AR-15 Model 01 rifles in December 1959. Colt marketed the Colt made ArmaLite AR-15 rifle to various military services around the world, after modifications, the new redesigned rifle was adopted by the United States military as the M16 rifle. Most Colt ArmaLite AR-15 rifles in U. S. service have long ago been upgraded to M16 rifle configuration, Colt continued to use the AR-15 trademark for its semi-automatic variants that were marketed to civilian and law-enforcement customers. The original AR-15 was a lightweight weapon, weighing less than 6 pounds with empty magazine. Later heavy-barrel versions of the civilian AR-15 can weigh upwards of 8.5 lb, patent 2,951,424 describes the cycling mechanism used in the original AR-15. The bolt carrier acts as a cylinder and the bolt itself acts as a stationary piston. This mechanism is called direct gas impingement, although it differs from prior gas systems. Stoner did not consider the AR-15 to be a direct impingement mechanism. Gas is tapped from the barrel as the bullet moves past a gas port located above the front sight base. The gas expands into the port and down a gas tube, here, the gas tube protrudes into a gas key, which accepts the gas and funnels it into the bolt carrier
8.
.450 Bushmaster
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The.450 Bushmaster is a rifle cartridge developed by Tim LeGendre of LeMag Firearms, and licensed to Bushmaster Firearms International. The.450 Bushmaster is designed to be used in the standard M16s and AR-15s, using modified magazines, the.450 Bushmaster is descended from the Thumper concept popularized by gun writer Jeff Cooper. Inspired by this, LeGendre developed his.45 Professional cartridge, Bushmaster and LeGendre approved the change from 1.771 to the now-standard 1.700, and a name change to.450 Bushmaster. The.450 Bushmaster is a rifle case, thus making efficient use of heavy.452 bullets. The cartridge is chambered in bolt action rifles by Ruger, AR-15 rifles, the cartridge fits single stacked in a standard AR-15 magazine with a single shot follower. A 10-round AR-15 magazine body will yield a 5-round magazine, a 20-round AR-15 magazine body will yield a 9-round magazine, hornady and Remington both now manufacture ammunition for the rifle
