Maximum Distance Terms
- Used in estimating the atmospheric conditions. This value is not
used unless the "Standard Conditions at Altitude" checkbox or the "Pressure is Corrected"
checkbox is checked.
- Ballistic Coefficient
- The ballistic coefficient for the bullet being used. It is almost
always obtained from the manufacturer, but can also be measured. The
ballistic coefficient is represents the ratio of the drag of the standard
(e.g. G1 standard bullet) bullet to that of the bullet you are shooting. A
ballistic coefficient of 0.100 means that your bullet has 10 times the drag
of the standard bullet.
- Bullet Library
- A drop down list showing all the buttons in the library. If
a bullet is selected, the trajectory is run with the selected bullet. If "None" is
selected, the entered BC, drag function and bullet weight are used.
Lapua bullets with "(CD)" in the description use the Drag Coefficients supplied by
Lapua instead of the ballistic coefficient. Bullets with "(Litz)" in the description
use Bryan Litz' BCs.
- Bullet Weight
- The weight of the bullet
- Drag Function
- A drag function (or G function) provides the forces on a standard
bullet for which the drag function was derived. A bullet's ballistic
coefficient then relates the drag on any bullet to that of the standard
- Muzzle Velocity
- The velocity of the bullet as either (1) measured at some distance
from the muzzle or (2) as estimated from reloading data.
- The barometric pressure. It may be corrected or uncorrected
depending on the state of the "Pressure is Corrected" checkbox.
- Pressure is Corrected
- Check this box if the pressure entered is a corrected station
pressure. If it is an absolute pressure, leave this unchecked.
- Relative Humidity
- Relative humidity (percent)
- Standard Conditions at Altitude
- When checked, the temperature, pressure and humidity for standard
atmospheric conditions at the entered altitude (always 0% at standard
conditions) are entered in the calculation. The standard used is the ICAO
- The measured or estimated air temperature.
- Maximum Distance
- Maximum distance achieved.
- Initial Angle
- The angle of the barrel relative to the ground.
- Terminal Range
- The distance achieved by the bullet for the elevation.
- Maximum Height
- The maximum height above the ground that the bullet achieved, in
- Terminal Angle
- The angle at which the bullet strikes the ground. Ninety degrees
is straight down.
- Terminal Velocity
- The final speed of the bullet in feet per second
- Terminal Energy
- Really the "Kinetic Energy" of the bullet. The kinetic energy is a
measure of the maximum amount of work (force time distance) an object can
do. [It is also a measure of the work done by the firearm/case/primer/powder
on the bullet.]
- Time of flight
- The time of flight of bullet in seconds.