Aiming at shooting at a moving target from a gun shot
(Pre-emption when shooting)
We know that when shooting a moving target aiming point must be moved (to choose) ahead of the direction of motion. The distance from the target to the aiming point is called anticipation. Anticipation for firing is because of the flight shot to the target, the target moves a certain distance. In addition, since the adoption of a hunter shooting solutions to pressing the trigger is about 0,15-0,35 seconds (so-called human error). The value of pre-emption depends on the speed of the target, the flight speed projectile (shot fired from a hunting rifle shot), the method of shooting - with a leash or with a fixed gun. When shooting with the leash (movement guns and therefore move the aiming point ahead of the target) is ruled out human error and the value of pre-emption less. Typically, most hunters shoot from the leash, if you can make aiming, otherwise on vskidku intuitively determining the aiming point.
Count and size of pre-emption to certain provisions of the hunter and game while shooting with the leash. (If you need to take into account the personal error, the following calculations must take into account the time spent on it). For the calculations necessary to know the speed of flight shots and movement game. These values are known and are described in various references for hunters. For example, the average velocity:
A duck are 16 m/s
Teal a whistler is 20 m/s
European hare-hare -8-10 m/s
Wild boar -4 m/s (by a lynx)
The rate of movement of shot is not permanent, thus falls in time not evenly - force of windage changes related to speed and determining an acceleration (braking). For simplification at a calculation will take advantage of given, resulted in different literature for block of shot hours on different distances. For an example will take firing on a кряковой duck and next to block of shot hours №5 on different distances:
10m - 0,03s
20m - 0,06 s
30m - 0,10 s
40m - 0,15 s
50m - 0,20 s
Speed of duck will take Vу = 16 m/s (other sizes over are brought in literature). Distance for example, to the duck of 30м. A shell (shot) will fly so far to the trajectory of duck after to = 0,10 s. For this time a duck (at motion athwart to direction of shot) will move on lу = Vу · to = 1,60 m Thus, forestaling, at distance to the duck of 30м and motion athwart direction of shot must take equal a 1,60 m If to take into account that size of duck approximately 50см, then forestaling at firing makes a 3 length of duck (for the speed taken by us duck 16 m/s).
At motion of game (ducks) under an acute angle to the trajectory of flight of shot, calculation a bit more difficult and forestaling depends on the size of this corner α. At a calculation some simplifications are accepted substantially not influencing on a result. The chart of firing, in-use at a calculation, is rotined on fig.1. So is initial distance to the target, l is a size of moving of target in perpendicular direction to the trajectory of flight of shot in times of flight of shot to the level of initial position of target, point In is a venue of shot and target, point With is target position in moment when a shot flies to т.А (level of initial position of target), Vуу is a constituent of target speed along direction of shot (axis At), Vух = constituent speeds are trajectories of flight of shot (axis X) athwart, α it is a corner between direction of flight of дрооби and targets (ducks).
Examining the resulted chart and accepting speed of flight of shot V after т.А (So =30м) permanent and equal 230 m/s (for a shot №5) can be got the following formula for the calculation of forestaling at firing:
to are block of shot hours to primary position of target ( So =30м, to =0,10с).
On fig.2 a chart, built on the basis of the resulted formula, dependence of size of forestaling from the corner of motion of target, is rotined. Evidently, that the noticeable correction of forestaling must be done at corners approximately 60 hail and less than.
It is necessary to consider also and displacement of aiming point at firing on large distances, which is conditioned operating of gravity on a shot (shell) and moving of it in times of flight in vertical direction. At firing a bullet from the threaded weapon adjustment of displacement on a height is foreseen the construction of breech-sight. Firing from a shot hunting gun is considered that is always conducted it is possible not to carry out on small distances and displacement of aiming point. Will estimate the size of moving of shell (shots №5) in vertical direction on condition that shot is fired an in horizontal direction. This moving can be defined on the known formula of kinematics:
Hпер = gt^2 /2,
t are block of shot hours, g is an acceleration of the free falling
On fig.3 the chart of dependence of size of moving of shot is rotined from distance, flying by it after a shot. A calculation is done for a shot №5 coming from the known and counted up block of such shot hours on different distances. From a chart evidently, that already in the distance the 40м moving arrives at the size of 11,3см. The sizes of moving resulted on graphic arts need to be taken into account for an increase exactness of firing.
In conclusion it should be said, that the information resulted higher is useful to understanding of necessity to take forestaling at firing on a locomotive target and picture of sizes of forestaling. In practice during hunt difficultly quickly and exactly to define the size of forestaling, because a the same game can move with different speed, under different corners, on different distance, there is not time for the calculation of forestaling. Exact enough determination of aiming point comes with experience.