What caliber? At long range, I would think the projectile would lose enough energy that it wouldn't be as effective as if it were in it's normal range.
Yes, you are right; and, in fact the bullet will in time begin to fly erratically and then tumble end over end. This is when marksmanship is effectively moot. Here's how it works:
Ballistics
There are three ballistic phases: internal, external, and terminal. External ballistics is everything about the performance of the bullet from the time it leaves the muzzle of the rifle to where it impacts the target. Our focus is on external ballistics since an understanding of it is paramount to a hitting a target at a prescribed distance.
Knowledge of basic external ballistic facts dispels misconceptions.
Gravity and air resistance have a constant and continuous effect on the bullet as it passes through air.
This constant effect causes the bullet path to be a definitive and uniform arc.
The sole purpose of spin which is imparted on the bullet from rifling is to stabilize the bullet to keep it from tumbling end over end.
The common cylindrical bullet has no loft capabilities as does an airplane wing.
A bullet fired from a true horizontal bore will begin to slow down and fall towards the earth immediately upon leaving the muzzle of the rifle.
Comprehension of trajectory helps the shooter understand the need to adjust sights to hit the target at any given distance.
A bullet flying through air is acted upon primarily by two forces, which change the direction and the velocity of the bullet’s motion.
Gravity causes the bullet to fall towards earth.
Air resistance causes the bullet to slow down, fly erratically, and tumble.
These forces are countered in three manners: (1) increase the angle of departure to counter the effect of gravity, and to allow the bullet to reach further distances, (2) impart spin, and (3) high velocities on the bullet to counter air resistance and allow the bullet to fly nose-on to a far distance.
Two basic concepts which can help us visualize how a bullet is sent through air are: the flight of a football and the spin of a children’s top.
Trajectory has three elements:
Line of sight, this is what we see when looking through our sights at the target.
Bullet path, the actual trajectory of the bullet from the time it leaves the bore.
Line of bore, the imaginary line from where the bullet rests in the bore to infinity. This is the path a bullet would take if gravity and air resistance were not factors. The bullet would in effect be a laser.
Increasing the angle of departure, such as using the hold over method of aiming, allows the bullet to hit a target at a greater distance. And, by increasing the angle of departure from horizontal, the line of sight will intersect the bullet path twice.
Now, about caliber: for 1000 yard shooting the minimum seen today is the .223 Round as fired from the match conditioned US Service Rifle. Usually, the cartridge will be loaded with a bullet which has a relatively high ballistic coefficient for the caliber. Even then, the bullet is greatly effected by wind. Most agree this sort of competition is very difficult.
