Targeting
The range to the target is measured or estimated as precisely as conditions permit and correct range estimation becomes absolutely critical at long ranges, because a bullet travels with a curved trajectory and the sniper must compensate for this by aiming higher at longer distances.[6] If the exact distance is not known the sniper may compensate incorrectly and the bullet path may be too high or low. As an example, for a typical military sniping cartridge such as 7.62x51mm NATO (.308 Winchester) M118 Special Ball round this difference (or “drop”) from 700 to 800 metres (770–870 yd) is 200 millimetres (7.9 in). This means that if the sniper incorrectly estimated the distance as 700 meters when the target was in fact 800 meters away, the bullet will be 200 millimeters lower than expected by the time it reaches the target.[6]
Laser rangefinders may be used, but are not preferred on the battlefield because a laser can be seen by both the sender and the receiver[citation needed]. One useful method is comparing the height of the target (or nearby objects) to their size on the mil dot scope, or taking a known distance and using some sort of measure (utility poles, fence posts) to determine the additional distance. The average human head is 150 millimeters (5.9 in) in width, average human shoulders are 500 millimeters (20 in) apart and the average distance from a person's pelvis to the top of their head is 1,000 millimeters (39 in).
To determine the range to a target without a laser rangefinder, the sniper may use the mil dot reticle on a scope to accurately find the range. Mil dots are used like a slide rule to measure the height of a target, and if the height is known, the range can be as well. The height of the target (in yards) ×1000, divided by the height of the target (in mils), gives the range in yards. This is only in general, however, as both scope magnification (7×, 40×) and mil dot spacing change. The USMC standard is that 1 mil (that is, 1 milliradian) equals 3.438 MOA (minute of arc, or, equivalently, minute of angle), while the US Army standard is 3.6 MOA, chosen so as to give a diameter of 1 yard at a distance of 1000 yards (or equivalently, a diameter of 1 meter at a range of 1 kilometer.) Many commercial manufacturers use 3.5, splitting the difference, since it is easier to work with.[6]
Explanation: 1 MIL = 1 milli-radian. That is, 1 MIL = 1x10^-3 radian. But, 10^-3 rad x (360 deg/ (2 x Pi) radians) = 0.0573 degrees. Now, 1 MOA = 1/60 degree = 0.01667 degrees. Hence, there are 0.0573/0.01667 = 3.43775 MOA per MIL, where MIL is defined as a milli-radian. On the other hand, defining a mil-dot by the US Army way, to equate it to 1-yard (1 m) at 1,000 yards (1,000 m), means the Army's mil-dot is approximately 3.6 MOA.
It is important to note that angular mil (mil) is only an approximation of a milliradian and different organizations use different approximations.
At longer ranges, bullet drop plays a significant role in targeting.[6] The effect can be estimated from a chart which may be memorized or taped to the rifle, although some scopes come with Bullet Drop Compensator (BDC) systems that only require the range be dialed in. These are tuned to both a specific class of rifle and specific ammunition. Every bullet type and load will have different ballistics. .308 Federal 175 grain (11.3 g) BTHP match shoots at 2,600 ft/s (790 m/s). Zeroed at 100 yards (100 m), a 16.2 MOA adjustment would have to be made to hit a target at 600 yards (500 m). If the same bullet was shot with 168 grain (10.9 g), a 17.1 MOA adjustment would be necessary.[6]
Shooting uphill or downhill is confusing for many because gravity does not act perpendicular to the direction the bullet is traveling. Thus, gravity must be divided into its component vectors. Only the fraction of gravity equal to the cosine of the angle of fire with respect to the horizon affects the rate of fall of the bullet, with the remained adding or subtracting negligible velocity to the bullet along its trajectory. To find the correct zero, the sniper multiplies the actual distance to the range by this fraction and aims as if the target were that distance away. For example, a sniper who observes a target 500 meters away at a 45-degree angle downhill would multiply the range by the cosine of 45 degrees, which is 0.707. The resulting distance will be 353 meters. This number is equal to the horizontal distance to the target. All other values, such as windage, time-to-target, impact velocity, and energy will be calculated based on the actual range of 500 meters. Recently, a small device known as a cosine indicator has been developed.[6] This device is clamped to the tubular body of the telescopic sight, and gives an indicative readout in numerical form as the rifle is aimed up or down at the target.[6] This is translated into a figure used to compute the horizontal range to the target.
Windage which plays a significant role, the effect increasing with wind speed or the distance of the shot. The slant of visible convections near the ground can be used to estimate crosswinds, and correct the point of aim. All adjustments for range, wind, and elevation can be performed by aiming off the target, called "holding over" or Kentucky windage.[6]Alternatively, the scope can be adjusted so that the point of aim is changed to compensate for these factors, sometimes referred to as "dialing in". The shooter must remember to return the scope to zeroed position. Adjusting the scope allows for more accurate shots, because the cross-hairs can be aligned with the target more accurately, but the sniper must know exactly what differences the changes will have on the point-of-impact at each target range.[6]
For moving targets, the point-of-aim is ahead of the target in the direction of movement. Known as "leading" the target, the amount of "lead" depends on the speed and angle of the target's movement as well as the distance to the target. For this technique, holding over is the preferred method.[6] Anticipating the behavior of the target is necessary to accurately place the shot.[6]
[edit]Hide sites and hiding techniques
The term "hide site" refers to a covered and concealed position from which a sniper and his team can conduct surveillance and/or fire at targets. A good hide conceals and camouflages the sniper effectively, provides cover from enemy fire and allows a wide view of the surrounding area.
The main purpose of ghillie suits and hide sites is to break up the outline of a person with a rifle.
Many snipers use ghillie suits to hide and stay hidden. Ghillie suits vary according to the terrain into which the sniper wishes to blend. For example, in dry, grassy wasteland the sniper will typically wear a ghillie suit covered in dead grass.
[edit]Tactics
[edit]Shot placement
Shot placement varies considerably with the type of sniper being discussed. Military snipers, who generally do not engage targets at less than 300 m (330 yd), usually attempt body shots, aiming at the chest. These shots depend on tissue damage, organ trauma, and blood loss to make the kill.
Police snipers who generally engage at much shorter distances may attempt more precise shot at particular parts of body or particular devices: in one event in 2007 in Marseille, a GIPNsniper took a shot from 80 m (87 yd) at the pistol of a policeman threatening to commit suicide, destroying the weapon and preventing him from killing himself.[39] Less lethal shots (at arms or legs) may be taken at criminals to sap their will to fight or reduce their mobility.
In a high-risk or instant-death hostage situation, police snipers may take head shots to ensure an instant kill. The snipers aim for the "apricot", or the medulla oblongata, located inside the head, a part of the brain that controls involuntary movement that lies at the base of the skull. Some ballistics and neurological researchers have argued that severing the spinal cord at an area near the second cervical vertebra is actually achieved,[citation needed] usually having the same effect of preventing voluntary motor activity, but the debate on the matter remains largely academic at present.
With moving targets it is necessary to lead the target to compensate for movement during the flight of the projectile.
[edit]Targets
Snipers can target personnel or materiel, but most often they target the most important enemy personnel such as officers or specialists (e.g. communications operators) so as to cause maximum disruption to enemy operations. Other personnel they might target include those who pose an immediate threat to the sniper, like dog handlers, who are often employed in a search for snipers.
A sniper identifies officers by their appearance and behavior such as symbols of rank, talking to radio operators, sitting as a passenger in a car, having military servants, binoculars/map cases or talking and moving position more frequently. If possible, snipers shoot in descending order by rank, or if rank is unavailable, they shoot to disrupt communications.
Since most kills in modern warfare are by crew-served weapons, reconnaissance is one of the most effective uses of snipers. They use their aerobic conditioning, infiltration skills and excellent long-distance observation equipment and tactics to approach and observe the enemy. In this role, their rules of engagement let them engage only high value targets of opportunity.
Some rifles, such as the Denel NTW-20 and Vidhwansak are designed for a purely anti-materiel (AM) role, e.g. shooting turbine disks of parked aircraft, missile guidance packages, expensive optics, and the bearings, tubes or wave guides of radar sets. A sniper equipped with the correct rifle can target radar dishes, water containers, the engines of vehicles, and any number of other targets. Other rifles, such as the .50 caliber rifles produced by Barrett and McMillan are not designed exclusively as AM rifles, but are often employed in such a way, providing the range and power needed for AM applications in a lightweight package compared to most traditional AM rifles. Other calibers, such as the .408 Cheyenne Tactical and the .338 Lapua Magnum are designed to be capable of limited AM application, but are ideally suited as long range anti-personnel rounds.
[edit]Relocating
Often in situations with multiple targets, snipers use relocation. After firing a few shots from a certain position, snipers move unseen to another location before the enemy can determine where he or she is and mount a counter-attack. Snipers will frequently use this tactic to their advantage, creating an atmosphere of chaos and confusion. In other, more rare situations, relocation is used to eliminate the factor of wind.
[edit]Sound masking
As sniper rifles are often extremely powerful and consequently loud, it is common for snipers to use a technique known as sound masking. When employed by a highly skilled marksman, this tactic can be used as a substitute for a noise suppressor. Very loud sounds in the environment, such as artillery shells air bursting or claps of thunder, can often mask the sound of the shot. This technique is frequently used in clandestine operations, infiltration tactics, and guerrilla warfare.
[edit]Psychological warfare
Due to the unexpected aspect of sniper fire, high lethality of aimed shots and frustration at the inability to locate and attack snipers, sniper tactics have a significant effect on morale. Extensive use of sniper tactics can be used as a psychological strategy in order to induce constant stress in opposing forces.
One may note that by many aspects (constant threat, high "per event" lethality, inability to strike back), the psychological impact imposed by snipers is quite similar to those of landmines, booby-traps, and IEDs.
Historically, captured snipers are often summarily executed. This happened during World War I,[40] and during World War II.[41] As a result, if a sniper is in imminent danger of capture, he may discard any items which might indicate his status as a sniper. The risk of captured snipers being summarily executed is explicitly referred to in Chapter 6 of US Army doctrine document FM 3-060.11 entitled 'SNIPER AND COUNTERSNIPER TACTICS, TECHNIQUES, AND PROCEDURES':
Historically, units that suffered heavy and continual casualties from urban sniper fire and were frustrated by their inability to strike back effectively often have become enraged. Such units may overreact and violate the laws of land warfare concerning the treatment of captured snipers. This tendency is magnified if the unit has been under the intense stress of urban combat for an extended time. It is vital that commanders and leaders at all levels understand the law of land warfare and understand the psychological pressures of urban warfare. It requires strong leadership and great moral strength to prevent soldiers from releasing their anger and frustration on captured snipers or civilians suspected of sniping at them.[42]
The negative reputation of snipers can be traced back to the American Revolution, when American "Marksmen" would intentionally target British officers, an act considered uncivilized by the British Army at the time (this reputation would be cemented during the Battle of Saratoga, when Benedict Arnold allegedly ordered his marksmen to target British General Simon Fraser, an act that would win the battle and French support).[7] However, the British side used specially selected sharpshooters as well, often German mercenaries.[7]
To demoralize enemy troops, snipers can follow predictable patterns. During the 26th of July Movement in the Cuban Revolution, the revolutionaries led by Fidel Castro always killed the foremost man in a group of President Batista's soldiers.[verification needed] Realizing this, none of Batista's men would walk first, as it was suicidal. This effectively decreased the army's willingness to search for rebel bases in the mountains. An alternative approach to this psychological process is to kill the second man in the row, leading to the psychological effect of nobody wanting to follow the "leader".
The phrase "one shot, one kill" has gained notoriety in popular culture as a glorification of the "sniper mystique". The phrase embodies the sniper's tactics and philosophy of stealth and efficiency. The term may mean that only a single round should be fired, as every shot fired assists the enemy in locating the sniper. As well, every shot should be accurately placed, in order to kill or severely wound the victim. Whether the phrase actually reflects reality is subject to debate, but it has been widely used in literature and movies.
[edit]Counter-sniper tactics
Main article: Counter-sniper tactics
The occurrence of sniper warfare has led to the evolution of many counter-sniper tactics in modern military strategies. These aim to reduce the damage caused by a sniper to an army, which can often be harmful to both combat capabilities and morale.
The risk of damage to a chain of command can be reduced by removing or concealing features which would otherwise indicate an officer's rank. Modern armies tend to avoid saluting officers in the field, and eliminate rank insignia on battle dress uniforms (BDU). Officers can seek maximum cover before revealing themselves as good candidates for elimination through actions such as reading maps or using radios.
Friendly snipers can be used to hunt the enemy sniper. Besides direct observation, defending forces can use other techniques. These include calculating the trajectory of a bullet bytriangulation. Traditionally, triangulation of a sniper's position was done manually, though radar-based technology has recently become available. Once located, the defenders can attempt to approach the sniper from cover and overwhelm him. The United States military is funding a project known as RedOwl (Robot Enhanced Detection Outpost With Lasers), which uses laser and acoustic sensors to determine the exact direction from which a sniper round has been fired.[43]
The more rounds fired by a sniper, the greater the number of chances a target has to locate him. Thus, attempts to draw fire are often made, sometimes by offering a helmet slightly out of concealment, a tactic successfully employed in the Winter War by the Finns known as "Kylmä-Kalle" (Cold Charlie).[44] They used a shop mannequin or other doll dressed as a tempting target, such as an officer. The doll was then presented as if it were a real man sloppily covering himself. Usually, Soviet snipers were unable to resist the temptation of an apparently easy kill. Once the angle where the bullet came from was determined, a large calibre gun, such as a Lahti L-39 "Norsupyssy" ("Elephant rifle") anti-tank rifle was fired at the sniper to kill him.
Other tactics include directing artillery or mortar fire onto suspected sniper positions, the use of smoke screens, placing tripwire-operated munitions, mines, or other booby-traps near suspected sniper positions. Even dummy trip-wires can be placed to hamper sniper movement. If anti-personnel mines are unavailable, it is possible to improvise booby-traps by connecting trip-wires to hand grenades, smoke grenades or flares. Though these may not kill the sniper, they will reveal the location of the sniper(s). Booby-trap devices can be placed near likely sniper hides, or along the probable routes to and from the positions. Knowledge of sniper field-craft will assist in this task.
One very old counter-sniper tactic is to tie rags onto bushes or similar items in suspected sniper hides. These rags flutter in the breeze creating random movements in the corner of the sniper's eye, which he/she will often find distracting. The greatest virtue of this tactic is its simplicty and ease of implementation; however, it is unlikely to prevent a skilled sniper from selecting targets, and may in fact provide a sniper with additional information about the wind near the target.
The use of canine units was very successful, especially during the Vietnam War. A trained dog can easily determine direction from the sound of the bullet, and will lie down with its head pointed at the origin of the gunshot.
[edit]Irregular and asymmetric warfare
Main article: Asymmetric warfare
The use of sniping (in the sense of shooting at relatively long range from a concealed position) to murder came to public attention in a number of sensational U.S. cases, including the Austin sniper incident of 1966, the John F. Kennedy assassination, and the Beltway sniper attacks of late 2002. However, these incidents usually do not involve the range or skill of military snipers; in all three cases the perpetrators had U.S. military training, but in other specialties. News reports will often (inaccurately) use the term sniper to describe anyone shooting with a rifle at another person.[citation needed]
Sniping has been used in asymmetric warfare situations, for example in the Northern Ireland Troubles, where in 1972, the bloodiest year of the conflict, the majority of the soldiers killed were shot by concealed IRA riflemen.[45] There were some instances in the early 1990s of British soldiers and RUC personnel being shot with .50 caliber Barrett rifles by sniper teams collectively known as the South Armagh sniper.[46] In Northern Ireland, in addition to the uses listed above, a sniper was quite often a form of bait called a "come-on", whereby the sniper's position would be made obvious to a British patrol so as to draw them into an ambush in their attempt to close with the sniper.[citation needed]
The sniper is particularly suited to combat environments where one side is at a disadvantage.[citation needed] A careful sniping strategy can use a few individuals and resources to thwart the movement or other progress of a much better equipped or larger force. Because of this perceived difference in force size, the sniping attacks may be viewed as the act of a few persons to terrorize (earning the moniker 'terrorists') a much larger, regular force — regardless of the size of the force the snipers are attached to. These perceptions stem from the precept that sniping, while effective in specific instances, is much more effective as a broadly deployed psychological attack (see elsewhere in article).
Snipers are less likely to be treated mercifully if captured by the enemy.[41] The rationale for this is that ordinary soldiers shoot at each other at 'equal opportunity' whilst snipers take their time in tracking and killing individual targets in a methodical fashion with a relatively low risk of retaliation.
No comments:
Post a Comment