Sniper rifle

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Sniper rifle is a term most frequently applied to rifles used by military or law enforcement to ensure accurate placement of shots at greater ranges than other small arms. A typical sniper rifle is built for optimal levels of accuracy, fitted with a telescopic sight and chambered for a military centrefire cartridge. The term is often used in the media to describe any type of accurised firearm fitted with a telescopic sight that is employed against human targets.

Contents 1 History 1.1 American Civil War 1.2 World War I 1.3 World War II 1.4 Vietnam War 2 Classification 2.1 Military 2.2 Law enforcement 3 Distinguishing characteristics 3.1 Telescopic sight 3.2 Action 3.3 Cartridge 3.4 Barrel 3.5 Stock 3.6 Sling 3.7 Other accessories 4 Accurising and maintenance 5 Capabilities 5.1 Accuracy 5.2 Maximum effective range 5.3 Range vs. accuracy 6 See also 7 Notes and references 8 Further reading 9 External links

[edit] History

The military role of sniper (a term derived from the bird snipe, which one would have to possess great ability with a rifle to hit) dates back to the turn of the 18th century, but the sniper rifle itself is a much more recent development. Advances in technology, specifically that of telescopic sights and more accurate manufacturing, allowed armies to equip specially-trained soldiers with rifles that would enable them to deliver precise shots over greater distances than regular infantry weapons. The rifle itself could be a standard rifle (at first, a bolt-action rifle); however, when fitted with a telescopic sight, it would become a sniper rifle.

[edit] American Civil War

Confederate troops equipped with barrel-length three power scopes mounted on the then premium British Whitworth Rifle had been known to kill Union officers at ranges bordering 800 yards, unheard of distances at that time.

[edit] World War I

The earliest sniper rifles were little more than conventional military or target rifles with long-range "peep sights" designed for use on the target range. Only from the beginning of the First World War did specially-adapted sniper rifles come to the fore, with one of the first scoped military sniper rifles being the SMLE Mk III* (HT).

[edit] World War II

Typical World War II-era sniper rifles were generally standard-issue rifles (hand-picked for accuracy) with a 2.5x telescopic sight and cheek-rest fitted, with the bolt turned down (if necessary) to allow operation with the scope affixed. By the end of the war, forces on all sides had specially-trained soldiers equipped with sniper rifles, and they have played an increasingly important role in military operations ever since.

Examples of sniper rifles used during World War II:

• Mosin-Nagant M91/30 used by the Soviet Union and Finland
• Mauser K98k used by Germany
• Lee-Enfield No 4 Mk I (T) used by the UK and Commonwealth
• SMLE Mk III* (HT) used by Australia
• Springfield M1903A4 used by the United States
• Arisaka Type 97 used by Japan

[edit] Vietnam War

• Mosin-Nagant M91/30 used by the North Vietnamese Army and the Viet Cong
• Winchester Model 70 30.06 rifle, used by the United States Army and the United States Marine Corps.

[edit] Classification

Modern sniper rifles can be generally divided into two basic classes: military and law enforcement.

[edit] Military

Sniper rifles aimed at military service often sacrifice a small degree of accuracy for durability, reliability, and ease of operation under battlefield conditions. Military snipers and sharpshooters might also be required to carry their rifles—along with other equipment—for long distances, and as such weight considerations are very important. Military organisations often operate under strict budgetary constraints, which could influence the type and quality of sniper rifles just as it would any other weapon system.

The following are examples of semi-automatic military sniper rifles. The cartridge used in each weapon is in parenthesis:

• MSG-90, used by the German Bundeswehr (7.62 x 51 mm NATO)
• Dragunov (SVD), used by former Soviet-aligned states (7.62 × 54 mm R)
• Mk 12 Mod 0/1, used by special operations units of the U.S. Army and the U.S. Navy (5.56 × 45 mm NATO)
• SR-25:
  • Mk 11 Mod 0 Sniper Weapon System, used by the USSOCOM and U.S. Marine Corps (7.62 × 51 mm NATO)
  • XM110 Semi-Automatic Sniper System, adopted by the U.S. Army (7.62 × 51 mm NATO)

The following are examples of bolt-action military sniper rifles. The cartridge used in each weapon is in parenthesis:

• Remington Model 700 rifle:
  • M24 Sniper Weapon System, used by the U.S. Army (7.62 × 51 mm NATO)
  • M40, used by the U.S. Marine Corps (7.62 × 51 mm NATO)
  • Mk 13 Mod 2, used by U.S. Special Operations Command forces (.300 Winchester Magnum)
• SV-98, an upgrade of the Dragunov SVD used in Russia (7.62 × 54 mm R)
• Accuracy International Arctic Warfare bolt-action rifle:
  • SR-98, used by the Australian Army (7.62 × 51 mm NATO)
  • L118A1, used by the British SAS (7.62 × 51 mm NATO)
  • PSG-90, used by the Swedish Army (7.62 × 51 mm NATO)
  • McMillan TAC-50, used by Canada
• Accuracy International AWM rifle:
  • L115A1, used by the British Army (.338 Lapua)
  • G22, used by the German Army (.300 Winchester Magnum)
• L42A1, formerly used by the British Army was a modified Lee-Enfield sniper rifle (7.62 × 51 mm NATO)
• Våpensmia NM149 (a modified Mauser design), used by the Norwegian Army (7.62 × 51 mm NATO)
• 7.62 TaK 85, used by the Finnish Army (7.62 × 54 mm R)
• PGM Ultima Ratio Hecate II, used by the French Army (.50 BMG, 12.7 x 99 mm)
• PGM Mini-Hecate .338, used by the Singapore Armed Forces and the Slovenian Armed Forces (.338 Lapua Magnum, 8.6 x 70 mm)

[edit] Law enforcement

Police/law enforcement (and, more recently, counter-terrorism) scenarios require the sniper or sharpshooter to hit a particular part of the aggressor's body, usually the head, but occasionally his/her weapon arm. For this reason, sniper rifles used by police forces are generally required to have greater accuracy over military rifles, but at shorter ranges—often less than 100 metres.

Some of the first examples of sniper rifles designed specifically to meet police requirements were those designed to meet West German police requirements following the Munich massacre at the 1972 Summer Olympics. The Heckler & Koch PSG1 is one of the rifles designed to meet these criteria, and is often referred to as an ideal example of this type of sniper rifle. The FN Special Police Rifle is another example of a rifle aimed at law enforcement rather than military agencies.

Some of the main differences of police sniper rifles when compared to military rifles are:

• Shorter overall length for increased manoeuvrability in urban areas
• Heavier weight
• Superior accuracy and tighter tolerances in construction
• Extreme outdoors durability is of less concern
• Higher price since budgetary restrictions on police departments often allow more expensive rifles to be acquired

[edit] Distinguishing characteristics

Sniper rifle features can vary widely depending on the specific tasks it is intended to perform. Features that may distinguish a sniper rifle from other weapons are:

• The presence of a telescopic sight
• Unusually long overall weapon length^[1]
• Stock designed for firing from a prone position
• Fitted with a bipod
• The range of accessories carried with the rifle
• Improved accuracy
• Not specifically designed for sporting use

[edit] Telescopic sight

Main article: telescopic sight

The single most important characteristic that sets a sniper rifle apart of other military or police small arms is the mounting of a telescopic sight, which is relatively easily distinguishable from smaller optical aiming devices found on some modern assault rifles and submachine guns.

A telescopic sight allows a person to see targets more precisely by virtue of the magnified image it offers, and therefore aim the rifle more accurately. The telescopic sights used on sniper rifles differ from other optical aiming devices in that they offer much greater magnification (more than 4x and up to 40x) and much larger objective lens (40 mm in diameter), resulting in a brighter image. Most telescopic lenses employed in military or police roles have special markings to aid the shot with the judgement of distance, which is an important factor in accurate shot placement (due to the curved trajectory of a bullet's path).

The flight time of the bullet, combined with the limited field of view of a sniper peering through a scope may allow an innocent victim to cross into a bullet's path.

[edit] Action

The choice between bolt-action and semi-automatic actions (more commonly recoil or gas operation) is usually determined by specific requirements of the sniper's role as envisioned in a particular organisation, with each design having advantages and disadvantages.

For a given cartridge, a bolt-action rifle has the following advantages:

• Cheaper to build and maintain
• More accurate, since there are fewer moving parts
• Manual case ejection, allowing for greater discretion
• Versatile fire-positioning, since there is no need for a large magazine
• Reliable, with fewer components that may fail or become jammed
• Lighter weight, once again due to fewer components

For semi-automatic actions, the following advantages are available:

• Cross-purpose use as both a battle rifle and a sniper rifle
• Greater volume of fire when needed in a suppressing support role
• Faster follow-up shots due to higher rate of fire
• Commonality of operation with issued service rifle, depending on system

A bolt-action is the most commonly used in both military and police roles due to its higher accuracy and ease of maintenance. Anti-materiel applications such as mine clearing and special forces operations tend to see a higher usage of semi-automatics.

A designated marksman rifle (DMR) is less specialised than a typical military sniper rifle, often only intended to extend the range of a group of soldiers. Therefore, when a semi-automatic action is used it is due to its ability to cross-over into roles similar to the roles of standard-issue weapons. There may also be additional logistical advantages if the DMR uses the same ammunition as the more common standard issue weapons. These rifles enable a higher volume of fire, but sacrifice some long-range accuracy. They are frequently built from existing selective fire battle rifles or assault rifles.

A police semi-automatic sniper rifle may be used in situations that require a single sniper to engage multiple targets in quick succession.

[edit] Cartridge

The cartridge determines some of the capabilities of a sniper rifle, and sets limitations on how it can be used. The following is a short list of only some of the issues that are affected by the calibre chosen:

• Effective range
• Ballistic performance
• Types of targets that can be effectively engaged
• Cost, and consequently, the number of rifles purchased and employed

In a military setting, logistical concerns are the primary determinant of the cartridge used, so sniper rifles are usually limited to rifle cartridges commonly used by the military force employing the rifle. Since large national militaries generally change slowly, military rifle ammunition is frequently battle-tested and well-studied by ammunition and firearms experts. Consequently, police forces tend to follow military practices in choosing a sniper rifle cartridge instead of trying to break new ground with less-perfected (but possibly better) ammunition.

Before the introduction of the 7.62 × 51 mm NATO in the 1950s, standard military calibers utilised were the .30-06 Springfield (United States), .303 British (United Kingdom) and 7.92 × 57 mm (8 mm Mauser) (Germany). The .30-06 Springfield continued in service with U.S. Marine Corps snipers during the Vietnam War in the 1970s, well after general adoption of the 7.62 × 51 mm. At the present time, in both the West and within NATO, 7.62 × 51 mm NATO (.308 Winchester) is currently the primary cartridge of choice for military and police sniper rifles.

Worldwide, the trend is similar. The preferred sniper rifle in Russia is another .30 caliber military cartridge—the 7.62 × 54 mm R, which has similar performance to the 7.62 × 51 mm NATO. This cartridge was introduced in 1891, and both Russian sniper rifles of the modern era, the Mosin-Nagant and the Dragunov (SVD), are chambered for it.

Certain commercial cartridges designed without the logistical constraints of most armies and only performance in mind have also gained popularity in the 1990s—these include the .338 Lapua and .300 Winchester Magnum. These cartridges offer better ballistic performance and greater effective range than the 7.62 × 51 mm NATO. Though they are not as powerful as .50 calibre cartridges (e.g. the .50 BMG), they also do not suffer any weight penalty as is the case for rifles chambered for .50 calibre ammunition, and, as such, offer a significant improvement over rifles chambered for the 7.62 × 51 mm NATO.

Snipers (mostly military) may also employ anti-materiel rifles in sniping roles against targets such as vehicles, equipment and structures, or for the long-range destruction of explosive devices. Although designed and employed primarily as anti-materiel rifles, they may also be used against personnel.

These rifles tend to be semi-automatic, and of a larger calibre than anti-personnel rifles, using .50 calibre (12.7 mm, such as the .50 BMG and Raufoss Mk211) or even 20 mm cartridges. Due to their considerable size and weight, snipers operating in 2- or 3-man teams becomes a necessity.

Examples of anti-materiel military sniper rifles:

• M82 SASR (Special Applications Scope Rifle) and M107 (.50 BMG)
• Denel NTW-20 (20 × 83.5 mm or 14.5 × 114 mm)

[edit] Barrel

Main article: Gun barrel

Rifle barrels employed in sniper rifles are normally of precise manufacture and of a heavier cross section than more traditional barrels in order to reduce the change in impact points between a first shot from a cold barrel and a follow-up shot from a warm barrel. Unlike many battle rifles and assault rifles, the bores are usually not chromed to avoid potential inaccuracy due to an uneven treatment.

When installed, barrels are often free-floated or installed so the barrel only contacts the rest of the rifle at the receiver to minimize the effects of pressure on the fore-end by slings, bipods, or the sniper's hands. The end of the barrel is usually crowned or machined to form a rebated area around the muzzle proper to avoid asymmetry or damage and therefore innacuracy. Alternately, some rifles like the Russian SVD or Walther WA2000 provide structures at the fore-end to provide tension on the barrel in order to counteract barrel droop and other alterations in barrel shape.

Another trait sometimes seen with sniper barrels are external longitudinal fluting that contributes to heat dissipation by increasing surface area while simultaneously decreasing the weight of the barrel.

Sniper rifle barrels may also utilise a threaded muzzle or combination device (muzzle brake or flash suppressor and attachment mount) to allow the fitting of a sound suppressor. These suppressors often have means of adjusting the point of impact while fitted.

Military sniper rifles tend to have longer barrels of around 23.5 inches (600 mm) to allow cartridge propellant to fully burn and attain the optimum combination of accuracy and bullet velocity. This reduces muzzle flash, helping to keep the sniper concealed. Police sniper rifles may use shorter barrels to improve handling characteristics. The shorter barrels' velocity loss is less important at closer ranges where projectile energy remains well in excess of that needed to reliably perform.

[edit] Stock

The most common special feature of a sniper rifle stock is the adjustable cheek piece, where the shooter's cheek meets the rear of the stock. For most rifles equipped with a telescopic sight, it is necessary to have this area raised slightly, because the telescope is positioned higher than iron sights, and the shooter should steady his cheek against a rifle while aiming. A cheek piece is simply a section of the stock that can be adjusted up or down to suit the individual shooter. To further aid this individual fitment, the stock can sometimes also be adjusted for length, often by varying the number of butt pad inserts at the rear of the stock where it meets the shooter's shoulder. Sniper stocks are typically designed to avoid making contact with the barrel of the weapon.

A permanently fixed or removable bipod attached to the rifle's forearm is another non-standard, but important piece of equipment. It acts as a steady and level object on which to rest the rifle which aids in accuracy.

[edit] Sling

An adjustable sling on the rifle is often employed. It is used by the sniper to achieve better stability when standing, kneeling, or sitting. The sniper uses the sling to "lock-in" by wrapping their non-firing arm into the sling forcing their arm to be still.

[edit] Other accessories

Sniper rifles often have specialised accessories, such as variable length gas-strut bipods.

[edit] Accurising and maintenance

Main article: accurizing

In the case of rifles designed specifically for sniping, the same techniques applied to any rifle to achieve long-range accuracy are used. Some of these techniques are described in the article on accurising a firearm and may include the following:

• A free-floating barrel, where the barrel is attached to the rifle at a single point, screwed into the action without touching the forearm — this prevents the barrel from being deflected when pressure is applied against the forearm.
• Heavier barrels to increase the resonant frequency and slow the rate of heating, which reduces thermal distortion of the barrel as more rounds are shot. This also increases the inertial mass of the rifle, thus reducing the felt recoil.
• Fluting on heavier barrels helps maintain the desired characteristics of a heavy barrel, but reduces the weight of the barrel.
• The end of the barrel may be counter-sunk a few millimetres to protect the critical exit-end of the rifling from damage.

When standard rifles are adapted for use as a sniper rifle common improvements on the action or internals include:

• Polishing the trigger sear to improve the feel of the trigger pull and therefore the shooter's trigger control.
• A low-mass (often titanium) hammer and firing pin reduce the time between the trigger pull and the primer ignition (called lock time). By reducing the time between the trigger being pulled and the bullet release, it reduces the distance that a human being's irreducible quiver can move the point of aim.

[edit] Capabilities

When examined individually, the capabilities of a sniper rifle may not seem unique, or even particularly extraordinary compared to other types of firearms. Certainly, on the face of it there is little to differentiate a specialist sniper rifle from a garden-variety scoped hunting rifle.

When taken as a whole, the subtle advantages possessed by a sniper rifle can allow a sniper to dominate an enemy who possesses far greater fighting capability. However, since sniping is a specialised role, it must be noted that the success of a sniper depends more on skills and training than on the particular rifle used.^[2]

[edit] Accuracy

Contrary to popular belief, sniper rifles are not necessarily characterised by exceptional accuracy—especially when compared to civilian sporting rifles, though they nearly always match or exceed the capabilities of other rifles in the military and police categories.^[3]

The United States military standards call for only 1 MOA,^[4] accuracy from a standard issue sniper rifle since accuracy is sacrificed in favor of low cost and reliability in harsh environments, as well as ease of operation and maintenance. This level of accuracy roughly translates into a variance in the bullet's point of impact of 8 inches at 800 yards, which is considered sufficient to ensure a high probability of hitting a human shape at that distance.

Although accuracy standards for police rifles do not widely exist, they are frequently seen with accuracy levels from 1.5 MOA to as high as 0.5 MOA^[5] — and occasionally as high as .25 MOA in the most expensive models.

For typical policing situations an accuracy level of 1 MOA is usually all that is required. This is because police typically employ their rifles at very short ranges.^[6][7] At 100 yards or less, a rifle with a relatively low accuracy of only 1 MOA should be able to repeatedly hit a 1 inch target. One inch is approximately the size of a man's thumb, which is smaller than the brain stem, the most prized target of a police sniper.^[8] However, a higher degree of accuracy is required for the rare occasion where a target needs to be engaged at a longer distance.^[9]

The following is a list of typical accuracies, for comparison:

• A common pistol may be capable of between 15 MOA and 30 MOA accuracy
• High end pistols may be capable of shooting 4 MOA.
• A military-issue battle rifle or assault rifle is usually capable of between 3 MOA and 6 MOA accuracy
• Civilian or police semi-automatic rifles are typically capable of less than 1 MOA to 4 MOA accuracy
• A common hunting rifle may be capable of 0.5 to 3 MOA accuracy
• A standard-issue military sniper rifle is typically capable of 0.5 to 2 MOA accuracy
• A police sniper rifle is typically capable of 0.25 to 1.5 MOA accuracy
• A competition target rifle may be capable of accuracy levels of 0.1 MOA or higher^{[citation needed]}
• Rifles designed for scientific testing of ammunition may be so accurate that sophisticated computer equipment is required to measure their accuracy^{[citation needed]}

[edit] Maximum effective range

Sniper rifles are characterised as having exceptional range capability compared to other small arms. This is true when properly maintained and employed by a trained marksman able to compensate for ballistic factors like crosswind and range estimation for long range engagements. Sniper rifles suffer the same line-of-sight limitations all direct fire weapons do and are often more subject to changes in ammunition than weapons designed for automatic fire or rapid semiautomatic fire.

Unlike police sniper rifles, military sniper rifles tend to be employed at the greatest possible distances so that range advantages like the increased difficulty to spot and engage the sniper can be exploited. However, machine guns, battle rifles, counter-sniper rifles and designated marksman rifles can reach or even exceed the range of a sniper rifle.

The most popular military sniper rifles (in terms o numbers in service) are chambered for .30 calibre ammunition, such as 7.62 × 51 mm NATO (.308 Winchester) and 7.62 x 54 R. Since sniper rifles of this class must compete with several other types of military weapons with similar range, snipers invariably must employ skilled fieldcraft to conceal their position.

The recent trend in specialised military sniper rifles is towards larger calibres that have greater range, such as .338 Lapua and .50 BMG. This allows snipers to take fewer risks, and spend less time finding concealment when facing enemies that are not equipped with similar weapons.

Approximate maximum effective ranges of common ammunition when used in a sniper rifle (lower figures are typical, higher figures are under ideal conditions):

Cartridge	Maximum effective range
5.56x45 NATO	400–600 m
.243 Winchester	600 m
7.62x51 NATO	800–1,000 m
7.62x54R	800–1,000 m
.300 Winchester Magnum	900–1,100 m
.338 Lapua	1,300–1,600 m
.50 BMG	1,500–2,000 m

[edit] Range vs. accuracy

Sniper rifles are considered ineffective beyond the distance a carefully-fired shot is guaranteed to strike the target. At longer ranges, a miss could occur that might endanger the sniper's mission. In those instances, other weapons may be preferred over sniper rifles, even though the situation may be an otherwise ideal job for a sniper rifle.

For example, in counter-sniper roles a sniper might spot a target that is out of range for a sniper rifle, and so the sniper may need to call upon a machine gunner to attack it. A machine gun using the same ammunition as the sniper rifle can be effective at a much greater range due to lower accuracy requirements for effective use.

Here is a simplified example to illustrate why, counter-intuitively, a less accurate weapon of the same calibre may actually have a greater effective range than a sniper rifle:

For human targets in military sniping, snipers do not aim at the person, instead they aim at a target circle^[10] The equations that describe the approximate relationships between range, accuracy, and the target circle, as used in this section, are as follows:

• Target circle (inches) x Accuracy MOA = Range metres
• Range meters / Accuracy MOA = Target circle inches

Also note that "target circle" is used exclusively even when "cone of fire" or "group size" may technically be more accurate. These terms have subtle differences that are not important for the purpose of this section, and they are left out to avoid introducing unnecessary complexity in illustrations and examples that have been intentionally simplified.

See also: Ballistics, and Accuracy and precision

The target circle is typically about 8 inches in diameter, corresponding to an imaginary circle on the vital area of a person's chest. For a common sniper rifle capable of 1 MOA accuracy, the maximum effective range (the range at which the bullet impact point is guaranteed to be within an 8-inch circle on the first shot) is about 800 metres.

In contrast, a machine gun using the same ammunition with a low accuracy of only 6 MOA will typically have a greater maximum effective range of about 1,100 meters. At that range and accuracy, a machine gun can have a larger target circle of about 66 inches. The machine gun's target circle is much larger due to its rapid fire capability, which allows a machine gun to strike with one or more hits and numerous misses at random locations within the target circle.

While a machine gun's large target circle means that its effective range can be longer than a sniper rifle's,^[11] The corresponding disadvantage is that the machine gun may need to fire dozens, and perhaps hundreds of rounds before scoring a hit.

[edit] See also

• Sniper
• Soviet sniper
• Designated marksman
• List of sniper rifles

[edit] Notes and references

[edit] Further reading

• Tobias, Ronald (1981). They Shoot to Kill: A Psycho-History of Criminal Sniping. Boulder, Colorado: Paladin Press. ISBN 0-87364-207-4. 
• De Haas, Frank (1995). Bolt Action Rifles. Krause Publications. ISBN 0-87349-168-8. 

[edit] External links

• Modern Firearms List of Sniper Rifles
• Mel's SniperCentral List of Sniper Rifles
• Sniper World
• Ultimate Sniper
• Mcmillan Tactical Stocks — Images of tactical stocks from the world's leading supplier manufacturer
• Tack Driving Tactical Rifle from Tac Ops — Detailed overview of the accurization process for a .25 MOA rifle
• Detailed accuracy articles, by famous barrel maker Dan Lilja
• Detail of Russian snipers and sniper rifles of World War Two by Chris Eger, military Historian