| Shooting From an Elevation |
Shooting From a Moving Platform |
Shooting at a Moving Target |
Being a projectile, a bullet's trajectory follows a parabolic path. "Bullet drop" is the distance the trajectory lays below the centerline of the bore. The line of sight crosses the trajectory at two distances. The distances at which the line of sight cross the bullet's trajectory are known as the weapon's "zero." At the firearm's zero there is no need for vertical correction on the firearms sights.
In the figure above, when fired, the bullet exits the barrel of the gun with a certain velocity, known as the "muzzle velocity." The vertical component of the velocity vector (y-axis) experiences an acceleration due to gravity in the negative y-direction. The velocity vector experiences acceleration in the negative direction due to drag while the bullet flies through the air. This drag causes increased bullet drop with respect to the distance traveled.
Shooting From an
Elevation
Shooting at a moving target requires one to "lead" one's
target. This means that one must take into account the
distance the target is away, the velocity vector that the
target has, and the velocity of the bullet once fired. A firearm with a horizontal zero of (RH)
will have a zero of (RS) if the line of sight is
at an angle of (theta) form the horizontal. RH
< RS when 0 < (magnitude of
theta) < pi. Therefore, to hit a target
at the distance of (RH) but in the direction (theta)
from the horizontal one must aim lower. It doesn't matter
if shooting at a target at a higher elevation respectively
or a lower elevation, either way one must aim lower.
When shooting at an angle (theta) the acceleration due to gravity of the bullet, perpendicular to the line of site, = (a) x cos(theta). This value is smaller than the acceleration due to gravity.perpendicular with the line of site, on the bullet when shooting with a horizontal line of site, which = (a). The smaller acceleration means that the bullet drop with respect to the line of site is smaller.
When shooting at an angle (theta) the acceleration due to gravity of the bullet, perpendicular to the line of site, = (a) x cos(theta). This value is smaller than the acceleration due to gravity.perpendicular with the line of site, on the bullet when shooting with a horizontal line of site, which = (a). The smaller acceleration means that the bullet drop with respect to the line of site is smaller.
Shooting at a moving target is the same as shooting on a moving platform. The only difference is that