Update 2-27

I have recently checked out the book "Understanding Firearm Ballistics" by Robert Rinker from the local library. Even though this book is hard to read, i have still used it to figure out more about the forces that effect a projectile while in flight.

The main factors that effect a projectile in flight are gravity, drag, and wind. Gravity is always acting on a projectile, pulling it down to earth and altering it from its original line of sight, this drop may not seem present in close range shots, but can be huge during longer range shooting. Drag or air resistance also decelerates the projectile while in flight. Wind effects the projectile by changing the path of trajectory. All these factors need to be accounted for when firing a rifle at long distances and corrections must be made.

The first thing that needs to be done before attempting any shooting at a target is to "zero" the weapon system you are using. This means to sight the gun in, or to see where the bullet is penetrating and line that up with the scope or sights that are used so that you know where you are going to hit when you pull the trigger. Most high-powered rifles are sighted in at 100 meters. When zeroing a weapon system, an initial shot is taken at a target then (if using a scoped sight) make the necessary corrections to move the crosshairs. Most scopes use a "click" system to sight in, one click moving crosshairs 1/4 of an inch at 100 yards. Two knobs are "clicked" when sighting in, a vertical knob and a horizontal knob. The shooter must D.O.P.E. ( data on previous engagements, or using previous shots to help predict where the next shot will impact) his scope and play with the clicks until the projectile hits where the crosshairs cross. Once a zero is made at a known distance, a shooter can remember that zero and adjust it to compensate for different ranges and other determining factors such as gravity, drag, and wind.

I am still learning more about how shooters can effectively make these corrections in their head on the fly while shooting at various targets, i have found some mathematical equations used for calculating the drop of the bullet, but I must research more before i fully understand what they mean and how they are used.