The ballistics of rifle is similar to any other projectile. Its path is
affected by gravity, air drag, atmospheric condition, wind, and
elevation changes. From the time the bullet leaves the muzzle of the
gun it has constant downward acceleration due to gravity. This downward
acceleration, causes the rate of bullet drop to get larger over
distance causing the bullet to have a parabolic path.
horizontal velocity is affected by the air resistance, also know as
drag. Each bullet also has a aerodynamic efficiency, also know as ballistic
coefficient. The higher the ballistic coefficient, the less the bullet
will be affected by air resistance. Based on bullet diameter and
velocity bullet drop can be estimated using the ballistic coefficient,
bullet drop tables are included in the back section of most reloading
manuals. This will give the ability to estimate the point of impact on
50 yard increments. The rifle must be sighted to a suitable range for
the targets expected to shoot.
path will need to be "sighted in" to match the line of sights. The
sights will have two points, where the point of impact is "zeroed" this
is because the rifle must be give a small aim above the target to
achieve a hit on the target. This makes the bullet have a "rise" before
it drops to hit the target at the distance it is sighted for. The
highest elevation of the bullet's path is one half the distance to the
zero distance. The standard for sighting in most hunting rifles is 200
yards. So, for 200 yard zero the bullet will have maximum "rise" at 100
yards. This will give the best possible sighting for most hunting
scenarios, and for most rifles the point of impact at 100 yards will
only be 1 or 2" high.
A long distance shooter or hunter may be prepared to change
the sighting by some sort of scope that can compensate for various
distance shots. May scopes have a reticle (cross hairs) that have
compensation for drop at different ranges beyond the sight in range.
Also may have dials that can enter a certain amount of "clicks" to
re-zero the rifle for a particular distance.