Long range shooting is a collective term for shooting disciplines where the shooter has to engage targets at such long distances that he has to calculate ballistics, especially in regards to wind. While shooting at shorter or "regular" ranges, one usually has to adjust the sights only in regards to gravity (which is constant) but, when the range is extended, wind drift will be the first factor affecting precision to the extent that it must be taken into account. Some would argue that long range shooting starts where assessment of wind, distance, and various atmospheric conditions are equally important for the results as pure shooting skills - meaning that even if one conducts a technically perfect shot, the shooter will miss the target because of incorrect calculations, or forgetting to take some element into consideration.
Video Long range shooting
Defining "long range"
The distances normally considered to be "long range" is caliber dependent, and long range may be defined as stretching the distance which the firearm and ammunition is capable of making consistent hits. Generally some may claim that for the .22 LR cartridge any distances over 100 meters (109 yards) is considered long range. For centerfire intermediate rifle calibers, some might say that everything over 300 to 400 m is considered long range, while some may claim that long range "starts" at 500 m. At the longer ranges the bullets will have a long flight time, and on days with good weather conditions one can spot the bullets spinning through the air. Some believe you really get "the feel" of long range shooting when you have time to see the bullet fly towards the target, and then dive below or swing past, just when you were sure you would hit it. Weather conditions may also affect what is considered long range for a given firearm configuration. For instance a professional shooter may be able to repeatably hit a given size target, i.e. a 100 mm ring, at 1000 meters (0.1 mil) in low and predictable wind, while the same 100 mm target may be near impossible to hit in heavy and varying wind at 200 meters (0.5 mil).
Maps Long range shooting
Calculation of trajectory
To succeed at long range shooting, one must have good shooting skill fundamentals, a rifle with good precision and as consistent ammunition as possible (mainly to achieve a consistent muzzle velocity). In addition, a variety of external factors must be taken into account with regard to ballistics calculation, including:
- Wind (both by the shooter and along the whole flight path to the target).
- Bullet shape and weight, trying to achieve the highest possible ballistic coefficient ("BC")
- Air pressure, altitude and (to a certain degree) humidity
- Temperature (including air, ammunition and barrel temperature)
- Spindrift, an effect caused by the rotation of the bullet
- Coriolis effect, caused by the Earth's rotation
- Mirage, which causes the shooter to hit high and to the side if there is a little wind
- Angle to the target (called "cosine angle"), either up or downhill
etc.
All these parameters can also be used at shorter distances, but the effect they pose is so small that they generally can be disregarded. At short distances the accuracy of the shooter, rifle and ammunition will often mask the very small effect these factors will have.
Wind estimation
For long shooting it is important to compensate for the wind by observing the wind's strength and direction, and then adjust the sights accordingly by rules of thumb. Wind force can be estimated by feeling the at the shooting position and seeing signs of it in the terrain. After for instance guessing the wind strength in meters per second (m/s), this wind value can be transferred to a sight correction in number of clicks. This rule of thumb applies to winds that come 90 degree from the side (full value), however winds coming from an angle must be taken into account by applying less sight adjustment.
- Long range wind estimation table based on the Beaufort scale
Competitions
There are many different long range disciplines, competing both at known (KD) and unknown distances (UKD), individually or in teams (shooter and spotter). In UKD competitions the marksman must also judge the distances, for example by comparing a known size target with angular mil hashmarks inside their scope (called "milling"]) to calculate the distance. Sometimes a laser rangefinder may also be used, if permitted.
Precision Rifle Competition
Precision Rifle Competitions is a relatively new long range competition format which seeks to find a balance between speed and precision, often involving movement and shooting from unusual positions with a time limit, at both known and unknown distances.
The competition seeks to find a balance between speed and precision at long range shooting. Shooting distances can vary from between 10 and 1,000 meters/ yards, and therefore the competitor must know the ballistics of his firearm very well. A competition usually consists of several courses of fire, and requires some physical activity since the shooter has a time limit to move between the various courses of fire. Each course usually has a set maximum time (par time), and the shooter is awarded points according to how many targets he manages to hit during that time. Both cardboard and steel targets are used, and the targets presented are usually relatively small. In the PRS-series for instance, the targets are usually between 0.3-0.9 MIL (3-9 cm at 100 m, approximately 1-3 MOA).
F-Class
F-Class is a rapidly growing long range shooting discipline internationally governed by the International Confederation of Fullbore Rifle Associations. F-Class carry many similarities to traditional high power rifle, except that it is only fired at distances between 300 and 1200 yards (or meters), and the targets are half the size of regular targets. They compete in two categories:
- F-Open (Open Class): All rifle calibers up to .35 may be used, along with a scope, and one can choose between using front rest and rear bag, or a bipod/ backpack. The weight limit including optics is 22 lbs (10 kg).
- F-TR ("Target", Standard Class): A restricted class permitting a scope, bipod/ backpack and rear bag (no front rest), but the rifle has to be of either caliber .223 Remington or .308 Winchester. In addition, the weight limit including optics is 18.15 lbs (8.25 kg).
Sight magnification
The ideal scope sight magnification for different types of long range shooting depends on application, scope quality and user preference. Different applications may have different shooting distances, light conditions, target sizes and target contrast against the background. Ideally scope magnification should be high enough while still being comfortable and safe to use.
Pros of high scope magnification are:
- Easier to see the target at distance.
- Easier to spot whether the round was a hit or miss, and easier to estimate sight corrections.
Cons of high scope magnification are:
- The sight picture appears to shake easier by movement of the shooter.
- Mirage becomes more visible.
- Less field of view makes it more difficult initially find the target, and to see the surroundings of the target.
- Less light transmission gives a darker image in the scope than on low magnification.
- Smaller exit pupil diameter makes it more difficult to get in the correct position behind the scope.
Mirage is a light distortion caused by temperature differences between the air and ground making it difficult to get a clear sight picture of the target. Mirage becomes more apparent the higher the magnification, but at what magnification mirage starts to become an issue depends on weather conditions.
References
See also
- Benchrest shooting
- External ballistics
External links
- Video: 2012 European F-Class Rifle Championships
- Video: Teamwork: Spotter & Shooter - Long Range Rifle Tip (by National Shooting Sports Foundation)
Source of the article : Wikipedia
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