Marines known as naval infantry, are an infantry force that specializes in the support of naval and army operations at sea and on land and air, as well as the execution of their own operations. In many countries, the marines are an integral part of that state's navy. In others, it is a separate organization altogether, such as in the United States, where the Marine Corps falls under the US Department of the Navy, yet it operates independently. Marines can fall under a country's army like the Troupes de marine and Givati Brigade. Tasks undertaken by marines have included: helping maintain discipline and order aboard the ship, the boarding of vessels during combat or capture of prize ships, providing manpower for raiding ashore in support of the naval objectives. With the industrialization of warfare in the 20th century the scale of landing operations increased. Marine forces evolved to specialize in the capabilities required for amphibious warfare. In the earliest day of naval warfare, there was little distinction between sailors and soldiers on a warship.
The oarsmen of Ancient Greek and Roman ships had to be capable of fighting the rowers of opposing ships hand-to-hand. The Roman Republic was the first to understand the importance of professional soldiers dedicated to melee combat onboard of ships. During the First Punic War, Roman crews remained inferior in naval experience to the Carthaginians and could not hope to match the Carthaginians in naval tactics, which required great fleet maneuverability and tactical experience; the Romans therefore employed a novel weapon which changed sea warfare to their advantage — they equipped their ships with the corvus, a long pivoting plank with a beak-like spike on the underside for hooking onto enemy ships developed earlier by the Syracusans against the Athenians during the Sicilian Expedition of the Peloponnesian War. Using it as a boarding bridge, Roman infantrymen were able to invade an enemy ship, transforming sea combat into a version of land combat, where the Roman legionaries had the upper hand.
During the early Principate, a ship's crew, regardless of its size, was organized as a centuria. Crewmen could sign on as naval infantry, rowers/seamen and various other jobs, though all personnel serving in the imperial fleet were classed as milites, regardless of their function; the Roman Navy's two fleet legions, I Adiutrix and II Adiutrix, were among the first distinct naval infantry units. The first organized marine corps was created in Venice by the Doge Enrico Dandolo when he created the first regiment of ten companies spread on several ships; that Corps participated to the conquest of Byzantium officially called " Fanti da Mar" in 1550. The Spanish king, Carlos I, assigned the naval infantry of the Compañías Viejas del Mar de Nápoles to the Escuadras de Galeras del Mediterráneo in 1537, progenitors of the current Spanish Navy Marines corps, making them the oldest marine corps still in active service in the world; the third oldest marine corps in the world was founded as the Terço of the Navy of the Crown of Portugal in 1618, predecessor to the modern Portuguese Marine Corps.
The English noun marine is from the adjective marine, meaning "of the sea", via French marin from Latin marinus itself from mare, from Proto-Indo-European *móri. The word marine was used for the marine-type forces of England; because of this use of "marine" to mean "navy", exact one-word translations for the English term "Marines" do not exist in many other languages, which can lead to misunderstandings when translating, with the notable exception of the Dutch word marinier. Marine forces in non-English speaking countries have names that translate in English to naval infantry or coastal infantry. In French-speaking countries, two phrases exist which could be translated as marine, "troupes de marine" and "fusiliers-marins"; the principal role of marine troops is military operations in the littoral zone. Marine units deploy from warships using boats, landing craft, amphibious vehicles or helicopters. Specialist units are trained in combat diving/combat swimming and parachuting; as well as amphibious operations, marine troops are used in a variety of naval roles.
Stationed at naval bases or forming marine detachments on board naval ships, they conduct small scale raiding, maritime boarding operations, security of naval vessels and bases and coastal missions, mess duty, field day operations. In addition to their primary roles, they perform other tasks, including special operations and land warfare, separate from naval operations.
A medal or medallion is a small portable artistic object, a thin disc of metal, carrying a design on both sides. They have a commemorative purpose of some kind, many are given as awards, they may be suspended from clothing or jewellery in some way. They are traditionally struck like a coin by dies. A medal may be awarded to a person or organization as a form of recognition for sporting, scientific, academic, or various other achievements. Military awards and decorations are more precise terms for certain types of state decoration. Medals may be created for sale to commemorate particular individuals or events, or as works of artistic expression in their own right. In the past, medals commissioned for an individual with their portrait, were used as a form of diplomatic or personal gift, with no sense of being an award for the conduct of the recipient. An artist who creates medals or medallions is called a "medalist". Medals have long been popular collectible items, in numismatics form a class called either exonumia or militaria.
In the proper use of the term, medallions are larger, starting at four inches across, are, as such too large to be worn comfortably, though in colloquial use, "medallion" is used to refer to a medal used as the pendant of a necklace, or for other types of medals. Medallions may be called "table medals" because they are too large to be worn and can only be displayed on a wall, table top, desk, or cabinet. Numismatists divide medals into at least seven classes: Awards: awarded to a person or organization as a form of recognition for sporting, scientific, academic, or various other achievements. Military awards and decorations are more precise terms for certain types of state decoration. Military decorations are in shapes such as crosses or stars, but are still loosely called "medals", as in the star-shaped American Medal of Honor. Commemoratives: created for sale to commemorate particular individuals or events, or as works of medallic art in their own right. Souvenirs: similar to a commemorative, but more focused on a place or event like state fairs, museums, historic sites, etc. and found for sale within their respective souvenir shops.
Religious: devotional medals may be worn for religious reasons. Portraits: produced to immortalize a person with their portrait. Artistic: made purely as an art object. Plaquettes are of this type. Society Medals: made for societies used as a badge or token of membership. First attested in English in 1578, the word medal is derived from the Middle French médaille, itself from Italian medaglia, from the post-classical Latin medalia, meaning a coin worth half a denarius; the word medallion has the same ultimate derivation, but this time through the Italian medaglione, meaning "large medal". There are two theories as for the etymology of the word medalia: the first being that the Latin medalia itself is derived from the adjective medialis meaning "medial" or "middle". Traditionally medals are stamped with dies on a durable metal flan or planchet, or cast from a mould; the imagery, which includes lettering, is in low relief. Circular medals are most common; the "decoration" types use other shapes crosses and stars.
These in particular come with a suspension loop, a wide coloured ribbon with a clip at the top, for attaching to clothing worn on the chest. The main or front surface of a medal is termed the obverse, may contain a portrait, pictorial scene, or other image along with an inscription; the reverse, or back surface of the medal, is not always used and may be left blank or may contain a secondary design. It is not uncommon to find only an artistic rendering on the obverse, while all details and other information for the medal are inscribed on the reverse; the rim is found only employed to display an inscription such as a motto, privy mark, engraver symbol, assayer’s marking, or a series number. Medals that are intended to be hung from a ribbon include a small suspension piece at the crest with which to loop a suspension ring through, it is through the ring that a ribbon is folded so the medal may hang pendent. Medals pinned to the breast use only a small cut of ribbon, attached to a top bar where the brooch pin is affixed.
Top bars may be hidden under the ribbon so they are not visible, be a plain device from which the ribbon attaches, or may be decorative to complement the design on the medal. Some top bars are contain a whole design unto themselves. Bronze has been the most common material employed for medals, due to its fair price range, ease with which to work when casting, the ample availability However, a wide range of other media have been used. Rarer metals have been employed, such as silver and gold, when wishing to add value beyond the mere artistic depiction, as well as base metals and alloys such as copper, iron, lead, zinc and pewter. Medals that are made with inexpensive material might be gilded, silver-plated, chased, or finished in a variety of other ways to improve their appearance. Medals have been made of rock, ivory, porcelain, terra cotta
Accurizing is the process of improving the accuracy and precision of a gun. For firearms, accuracy is the ability to hit what one is aiming at, precision is the ability to hit the same place over and over again in a repeatable fashion. Both are the goals of accurizing, which concentrates on four different areas: Usability: Enhancements that give the shooter a firmer and more consistent hold on the firearm, as well as a more consistent trigger pull. Better design ergonomics is employed, such as adjustable buttstocks and grips with more vertical angles that are natural to the human hand and wrist. Spirit levels are mounted to minimize canting, which can vary the points of impact. Weapon mounts such as bipod, benchrest, shooting sticks or sandbags can provide a more stable and relaxed platform for the shooter, devices such as muzzle brake or compensator can be used to help counter the muzzle rise from recoils; the use of suitable slings can help shooters to stabilize the aim when shooting off-hand while standing or squatting.
Tolerances: Parts that better fit together will shift less, or shift more under recoil. Rifle bedding is one of the most common practices of such accurizing procedure. Adequate screw torque setting between the action and the stock is important for the overall rigidity of the system; some companies, such as Savage Arms, have introduced features like floating bolt head to provide better bolt-breech engagement and sealing of the barrel breech. Harmonics: The act of firing a gun generates a rapid pressure increase within the barrel bore, causing the barrel to resonate and vibrate in a whip-like fashion; the resultant harmonic oscillations of the barrel affect the terminal phase of the projectile's internal ballistics and in turn the initial status of its external ballistics, therefore need to be minimized or tuned to limit their effects on accuracy. The harmonic effects are proportional to the square of the barrel length, so are only of concern in long guns such as rifles but not handguns; some external accessories, called tuners or de-resonators, can be mounted onto the barrel to modify the harmonic wave pattern so that the node is shifted as near to the muzzle as possible.
Airguns have lower barrel pressure, therefore are far less affected by barrel harmonics than firearms. Projectile propulsion consistency: In airguns, the inbuilt powerplants themselves provide the propulsive force to the projectile, so tuning the gun alone is sufficient for accurizing as long as the projectiles' weights and shapes are uniform. Firearms, rely purely on the powder within a cartridge to provide propulsive force, any slight variations in powder load and rate of combustion will affect the internal ballistics of the gun if the projectile weights and shape are the same; this means that in addition to the gun itself, consistent ammunition performance is extremely critical for accuracy with firearms. While some manufacturers produce match-grade ammunition with smaller tolerances, it is common for shooters of high-precision disciplines to handload and fine-tune their own ammunition. Furthermore, the rapid gas expansion that occurs when the projectile leaves the muzzle barometrically affects flight behaviour, so muzzle devices such as flash hider and suppressor can be used to modulate the escaping gas and improve the consistency of shots.
The key to an accurate firearm is consistency. Getting everything to happen the same way for every shot is key to producing small groupings, there are a large number of issues to be addressed in achieving an accurate firearm; the keys to firing an accurate shot are a firm but not overtight grip, the ability to get a good sight picture and a controlled squeeze of the trigger. The ability to manage recoil is important in recoiling calibers, both to aid in possible additional shots, to prevent the user from developing a fear of the recoil. Determining accuracy is not always a straightforward task, as it depends on a large number of variables; the accuracy of a shot relies on many different factors, which can be broken down into three broad categories: the firearm, the cartridge, the shooter. Accurizing refers to the processes that are applied to the firearm. Techniques relating to producing accurate ammunition are covered in internal and external ballistics, handloading, just like accurizing a firearm, the goal is to produce the most consistent possible results.
The shooter must be consistent, this means that the fundamentals of marksmanship have to be followed rigorously. It's common to use a benchrest or a vise when evaluating ammunition or a weapon for accuracy in order to eliminate human error. Since adjusting the point of impact to match the point of aim is simple with any type of adjustable sights, the primary goal of accurizing is to increase the precision of the firearm, measured by looking at the dispersion of a number of shots fired at the same point of aim. An ideal group would be one where all shots land in a hole no larger than the diameter of a single bullet; the most common way of measuring groups is to measure the edge to edge distance of the farthest holes, subtract the bullet diameter, which gives the center to center or c-c measurement of the group. This can be expressed in angular measures. Groups for rifles are traditionally shot at either 100 yards. At 100 yd a
United States Army
The United States Army is the land warfare service branch of the United States Armed Forces. It is one of the seven uniformed services of the United States, is designated as the Army of the United States in the United States Constitution; as the oldest and most senior branch of the U. S. military in order of precedence, the modern U. S. Army has its roots in the Continental Army, formed to fight the American Revolutionary War —before the United States of America was established as a country. After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784 to replace the disbanded Continental Army; the United States Army considers itself descended from the Continental Army, dates its institutional inception from the origin of that armed force in 1775. As a uniformed military service, the U. S. Army is part of the Department of the Army, one of the three military departments of the Department of Defense; the U. S. Army is headed by a civilian senior appointed civil servant, the Secretary of the Army and by a chief military officer, the Chief of Staff of the Army, a member of the Joint Chiefs of Staff.
It is the largest military branch, in the fiscal year 2017, the projected end strength for the Regular Army was 476,000 soldiers. S. Army was 1,018,000 soldiers; as a branch of the armed forces, the mission of the U. S. Army is "to fight and win our Nation's wars, by providing prompt, land dominance, across the full range of military operations and the spectrum of conflict, in support of combatant commanders"; the branch participates in conflicts worldwide and is the major ground-based offensive and defensive force of the United States. The United States Army serves as the land-based branch of the U. S. Armed Forces. Section 3062 of Title 10, U. S. Code defines the purpose of the army as: Preserving the peace and security and providing for the defense of the United States, the Commonwealths and possessions and any areas occupied by the United States Supporting the national policies Implementing the national objectives Overcoming any nations responsible for aggressive acts that imperil the peace and security of the United StatesIn 2018, the Army Strategy 2018 articulated an eight-point addendum to the Army Vision for 2028.
While the Army Mission remains constant, the Army Strategy builds upon the Army's Brigade Modernization by adding focus to Corps and Division-level echelons. Modernization, reform for high-intensity conflict, Joint multi-domain operations are added to the strategy, to be completed by 2028; the Continental Army was created on 14 June 1775 by the Second Continental Congress as a unified army for the colonies to fight Great Britain, with George Washington appointed as its commander. The army was led by men who had served in the British Army or colonial militias and who brought much of British military heritage with them; as the Revolutionary War progressed, French aid and military thinking helped shape the new army. A number of European soldiers came on their own to help, such as Friedrich Wilhelm von Steuben, who taught Prussian Army tactics and organizational skills; the army fought numerous pitched battles and in the South in 1780–1781, at times using the Fabian strategy and hit-and-run tactics, under the leadership of Major General Nathanael Greene, hit where the British were weakest to wear down their forces.
Washington led victories against the British at Trenton and Princeton, but lost a series of battles in the New York and New Jersey campaign in 1776 and the Philadelphia campaign in 1777. With a decisive victory at Yorktown and the help of the French, the Continental Army prevailed against the British. After the war, the Continental Army was given land certificates and disbanded in a reflection of the republican distrust of standing armies. State militias became the new nation's sole ground army, with the exception of a regiment to guard the Western Frontier and one battery of artillery guarding West Point's arsenal. However, because of continuing conflict with Native Americans, it was soon realized that it was necessary to field a trained standing army; the Regular Army was at first small and after General St. Clair's defeat at the Battle of the Wabash, the Regular Army was reorganized as the Legion of the United States, established in 1791 and renamed the United States Army in 1796; the War of 1812, the second and last war between the United States and Great Britain, had mixed results.
The U. S. Army did not conquer Canada but it did destroy Native American resistance to expansion in the Old Northwest and it validated its independence by stopping two major British invasions in 1814 and 1815. After taking control of Lake Erie in 1813, the U. S. Army seized parts of western Upper Canada, burned York and defeated Tecumseh, which caused his Western Confederacy to collapse. Following U. S. victories in the Canadian province of Upper Canada, British troops who had dubbed the U. S. Army "Regulars, by God!", were able to capture and burn Washington, defended by militia, in 1814. The regular army, however proved they were professional and capable of defeating the British army during the invasions of Plattsburgh and Baltimore, prompting British agreement on the rejected terms of a status quo ante bellum. Two weeks after a treaty was signed, Andrew Jackson defeated the British in the Battle of New Orleans and Siege of Fort St. Philip, became a national hero. U. S. troops and sailors captured HMS Cyane and Penguin in the final engagements of the war.
Per the treaty, both sides (the United S
A telescopic sight called a scope, is an optical sighting device, based on a refracting telescope. They are equipped with some form of graphic image pattern mounted in an optically appropriate position in their optical system to give an accurate aiming point. Telescopic sights are used with all types of systems that require accurate aiming but are most found on firearms rifles. Other types of sights are iron sights, reflector sights, laser sights; the optical components may be combined with optoelectronics to form a night scope. The first experiments directed to give shooters optical aiming aids go back to the early 17th century. For centuries different optical aiming aids and primitive predecessors of telescopic sights were created that had practical or performance limitations. In 1776 Charles Willson Peale attempted to have a telescope mounted to a rifle as a sighting aid, but without the ability to mount the telescope due to the lens arrangement to set it back from the rifleman's eye, the telescope impacted the rifleman's eye when firing due to recoil.
Thus, the attempt was not a success. The first documented telescopic rifle sight was invented between 1835 and 1840. In a book titled The Improved American Rifle, written in 1844, civil engineer John R. Chapman documented the first telescopic sights made by Morgan James of Utica, New York. Chapman gave James the concepts and some of the design, whereupon they produced the Chapman-James sight. In 1855, William Malcolm of Syracuse, NY began producing his own sight. Malcolm used an original design incorporating achromatic lenses like those used in telescopes, improved the windage and elevation adjustments, they were between twenty magnification. Malcolm's and those made by L. M. Amidon of Vermont. Still other telescopic rifle sights of the same period were the Parker Hale. An early practical refractor telescope based telescopic sight was built in 1880 by August Fiedler, forestry commissioner of Prince Reuss. Telescopic sights with extra long eye relief became available for handgun and scout rifle use.
A historic example of a telescopic sight with a long eye relief is the German ZF41, used during World War II on Karabiner 98k rifles. An early example of a man portable telescopic sight for low visibility/night use is the Zielgerät 1229 known by its code name Vampir; the ZG 1229 Vampir was a Generation 0 active infrared night vision device developed for the Wehrmacht for the StG 44 assault rifle, intended for night use. The issuing of the ZG 1229 Vampir system to the military started in 1944 and it was used on a small scale in combat from February 1945 until the final stages of World War II. Telescopic sights are classified in terms of the optical magnification and the objective lens diameter, e.g. 10×50. This would denote 10 times magnification with a 50 mm objective lens. In general terms, larger objective lens diameters, due to their ability to gather larger amounts of light, provide a larger exit pupil and hence provide a brighter image at the eyepiece. On fixed magnification sights the magnification power and objective diameter should be chosen on the basis of the intended use.
There are telescopic sights with variable magnification. The magnification can be varied by manually operating a zoom mechanism. Variable sights offer more flexibility regarding shooting at varying ranges and light conditions and offer a relative wide field of view at lower magnification settings; the syntax for variable sights is the following: minimal magnification – maximum magnification × objective lens, for example, 3–9×40. Confusingly, some older telescopic sights of German or other European manufacture, have a different classification where the second part of the designation refers to'light gathering power.' In these cases, a 4×81 sight would be presumed to have a brighter sight picture than a 2.5×70, but the objective lens diameter would not bear any direct relation to picture brightness, as brightness is affected by the magnification factor. Objective lenses on early sights are smaller than modern sights, in these examples the 4×81 would have an objective 36 mm diameter and the 2.5×70 should be 21 mm Telescopic sights are designed for the specific application for which they are intended.
Those different designs create certain optical parameters. Those parameters are: Magnification — The ratio of the focal length of the eyepiece divided into the focal length of the objective gives the linear magnifying power of telescopes. A magnification of factor 10, for example, produces an image as if one were 10 times closer to the object; the amount of magnification depends upon the application. Lower magnifications lead to less susceptibility to shaking. A larger magnification leads to a smaller field of view. Objective lens diameter – The diameter of the objective lens determines how much light can be gathered to form an image, it is expressed in millimeters. Field of view — The field of view of a telescopic sight is determined by its optical design, it is notated in a linear value, such as how many meters in width will be seen at 100 m, or in an angular value of how many degrees can be viewed. Exit pupil — Telescopic sights concentrate the light gathered by the objective into a beam, the exit pupil, whose diameter is the objective diameter divided by the magnifying power.
For maximum effective
A sniper is a military/paramilitary marksman who operates to maintain effective visual contact with and engage enemy targets from concealed positions or at distances exceeding the target's detection capabilities. Snipers have specialized training and are equipped with high-precision rifles and high-magnification optics, feed information back to their units or command headquarters. In addition to marksmanship and long range shooting, military snipers are trained in a variety of tactical techniques: detection and target range estimation methods, field craft, special reconnaissance and observation and target acquisition; the verb "to snipe" originated in the 1770s among soldiers in British India in reference to shooting snipes, considered an challenging game bird for hunters. The agent noun "sniper" appears by the 1820s; the term sniper was first attested in 1824 in the sense of the word "sharpshooter". A somewhat older term is "sharp shooter", a calque of 18th-century German Scharfschütze, in use in British newspapers as early as 1801.
Different countries use different military doctrines regarding snipers in military units and tactics. A sniper's primary function in modern warfare is to provide detailed reconnaissance from a concealed position and, if necessary, to reduce the enemy's fighting ability by shooting high-value targets and in the process pinning down and demoralizing the enemy. Typical sniper missions include managing intelligence information they gather during reconnaissance and surveillance, target acquisition for air-strikes and artillery, assist employed combat force with fire support and counter-sniper tactics, killing enemy commanders, selecting targets of opportunity, destruction of military equipment, which tend to require use of anti-materiel rifles in the larger calibers such as the.50 BMG, like the Barrett M82, McMillan Tac-50, Denel NTW-20. Soviet- and Russian-derived military doctrines include squad-level snipers. Snipers have been demonstrated as useful by US and UK forces in the recent Iraq campaign in a fire support role to cover the movement of infantry in urban areas.
Military snipers from the US, UK, other countries that adopt their military doctrine are deployed in two-man sniper teams consisting of a shooter and spotter. A common practice is for a spotter to take turns in order to avoid eye fatigue. In most recent combat operations occurring in large densely populated towns, such as Fallujah, two teams would be deployed together to increase their security and effectiveness in an urban environment. A sniper team would be armed with its long-range weapon and a shorter-ranged weapon in case of close contact combat; the German doctrine of independent snipers and emphasis on concealment, developed during the Second World War, has been most influential on modern sniper tactics, is used throughout Western militaries. Sniper rifles are classified as crew-served. A sniper team consists of a combination of one or more shooters with force protection elements and support personnel: such as a spotter or a flanker. Within the Table of Organization and Equipment for both the United States Army and the U.
S. Marine Corps, the operator of the weapon has an assistant trained to fulfill multiple roles, in addition to being sniper-qualified in the operation of the weapon; the shooter fires the shot while the spotter assists in observation of targets, atmospheric conditions and handles ancillary tasks as immediate security of their location, communication with other parties. A flanker's task is to observe areas not visible to the sniper or spotter and assist with the team's perimeter and rear security, therefore flankers are armed with an assault rifle or battle rifle. Both spotter and flanker carry associated equipment; the spotter detects and assigns targets and watches for the results of the shot. Using a spotting scope or a rangefinder, the spotter will read the wind by using physical indicators and the mirage caused by the heat on the ground. In conjunction with the shooter, the spotter will make calculations for distance, angle shooting, mil dot related calculations, correction for atmospheric conditions and leads for moving targets.
It is not unusual for the spotter to be equipped with a notepad and a laptop computer for performing these calculations. Law enforcement snipers called police snipers, military snipers differ in many ways, including their areas of operation and tactics. A police sharpshooter is part of a police operation and takes part in short missions. Police forces deploy such sharpshooters in hostage scenarios; this differs from a military sniper. Sometimes as part of a SWAT team, police snipers are deployed alongside negotiators and an assault team trained for close quarters combat; as policemen, they are trained to shoot only as a last resort, when there is a direct threat to life. Police snipers operate at much shorter ranges than military snipers under 100 meters and sometimes less than 50 meters. Both types of snipers do make difficult shots under pressure, perform one-shot kills. Police units that are unequipped for tactical operations may rely on
A rifle is a portable, long-barrelled firearm designed for long-range precision shooting, to be held with both hands and braced against the shoulder for stability during firing, with a barrel that has a helical pattern of grooves cut into the bore walls. The term was rifled gun, with the word "rifle" referring to the machining process of creating grooving with cutting tools, is now used for any long handheld device designed for aimed discharge activated by a trigger, such as air rifles and the personnel halting and stimulation response rifle. Rifles are used in warfare, law enforcement and shooting sports. Like all typical firearms, a rifle's projectile is propelled by the contained deflagration of a combustible propellant compound, although other means such as compressed air are used in air rifles, which are popular for vermin control, hunting small game, formal target shooting and casual shooting; the raised areas of the rifling are called "lands," which make contact with the projectile, imparting a spin around the longitudinal axis of the barrel.
When the projectile leaves the barrel, this spin lends gyroscopic stability to the projectile and prevents tumbling, in the same way that a properly spirally thrown American football or rugby ball behaves. This thus improves range and accuracy. Rifles only fired a single projectile with each squeeze of the trigger. Modern rifles are classified as single shot, bolt action, semi-automatic, or automatic. Single shot, bolt action, semi-automatic rifles are limited by their designs to fire a single shot for each trigger pull. Only automatic rifles are capable of firing more than one round per trigger squeeze. Modern automatic rifles overlap to some extent in function with machine guns. In fact, many light machine guns are adaptations of existing automatic rifle designs. A military's light machine guns are chambered for the same caliber ammunition as its service rifles; the difference between an automatic rifle and a machine gun comes down to weight, cooling system, ammunition feed system. Rifles, with their lighter components and smaller capacity magazines, are incapable of sustained automatic fire in the way that machine guns are.
Modern military rifles are fed by magazines, while machine guns are belt-fed. Many machine guns allow the operator to exchange barrels in order to prevent overheating, whereas rifles do not. Most machine guns fire from an open bolt in order to reduce the danger of "cook-off", while all rifles fire from a closed bolt for accuracy. Machine guns are crewed by more than one soldier; the term "rifle" is sometimes used to describe larger rifled crew-served weapons firing explosive shells, for example, recoilless rifles and naval rifles. In many works of fiction a rifle refers to any weapon that has a stock and is shouldered before firing if the weapon is not rifled or does not fire solid projectiles; the origins of rifling are difficult to trace, but some of the earliest practical experiments seem to have occurred in Europe during the 15th century. Archers had long realized that a twist added to the tail feathers of their arrows gave them greater accuracy. Early muskets produced large quantities of smoke and soot, which had to be cleaned from the action and bore of the musket either through the action of repeated bore scrubbing, or a deliberate attempt to create "soot grooves" that would allow for more shots to be fired from the firearm.
This might have led to a perceived increase in accuracy, although no one knows for sure. True rifling dates from the mid-15th century, although military commanders preferred smooth bore weapons for infantry use because rifles were much more prone to problems due to powder fouling the barrel and because they took longer to reload and fire than muskets. Rifles were created as an improvement in the accuracy of smooth bore muskets. In the early 18th century, Benjamin Robins, an English mathematician, realized that an elongated bullet would retain the momentum and kinetic energy of a musket ball, but would slice through the air with greater ease; the black powder used in early muzzle-loading rifles fouled the barrel, making loading slower and more difficult. Their greater range was considered to be of little practical use, since the smoke from black powder obscured the battlefield and made it impossible to target the enemy from a distance. Since musketeers could not afford to take the time to stop and clean their barrels in the middle of a battle, rifles were limited to use by sharpshooters and non-military uses like hunting.
Muskets were smoothbore, large caliber weapons using ball-shaped ammunition fired at low velocity. Due to the high cost and great difficulty of precision manufacturing, the need to load from the muzzle, the musket ball was a loose fit in the barrel. On firing the ball bounced off the sides of the barrel when fired and the final direction on leaving the muzzle was unpredictable; the performance of early muskets defined the style of warfare at the time. Due to the lack of accuracy, soldiers were deployed in long lines to fire at the opposing forces. Precise aim was thus not necessary to hit an opponent. Muskets were used for comparatively rapid, imprecise