BC

[?] Ballistic Coefficient Ballistic Coefficient (BC) to either the G1 standard or the G7 standard. If both G1 and G7 data are provided, it is best to choose the G7 value for HPBT type bullets.

Weight

[?]Bullet Weight The weight of the bullet as provided by the manufacturer.

Diameter

[?]Bullet Diameter The diameter of the bullet as provided by the manufacturer.

Length

[?]Bullet Length The length of the bullet as provided by the manufacturer. If unknown, mulitiply bullet diameter by 4.2.

Muzzle Velocity

[?] Muzzle Velocity How fast the bullet leaves the rifle as measured by a chronograph. For very accurate results, remember to account for the velocity lost in the 10-15 feet between the muzzle and the chronograph. As a rule of thumb, a bullet looses 5-15 fps in this short distance.

Zero Range

[?]Zero Range This is the range at which your rifles Point Of Aim (POI) equals the Point Of Impact (POI). A Zero range of 100 yards or meters is encouraged for several reasons, including insensitivity to atmospheric conditions, and accounting for inclined fire effects.

Sight Height

[?]Sight Height How high the scope centerline is above the bore centerline. This is typically between 1.5" and 3.5".

Twist Rate

[?]Twist Rate How many "inches per turn" is your rate of rifling twist. This number is used along with other inputs to determine the stability and related trajectory metrics. Typical value for this input is between 1:7" and 1:13".

Wind Speed

[?]Wind Speed The absolute magnitude of the wind speed.

Wind Direction

[?]Wind Direction [Clock Direction] The direction in which the wind is coming from in terms of clock hands. Example: If the wind is blowing from the left to right and slightly into your face, it would be 10 or 11 o'clock wind.

Temperature

[?]Air Temperature The atmospheric temperature. Because there is a great sensitivity to atmospheric temperature, it is recommended that this data be provided by using a local weather station or handheld weather meter.

Pressure

[?]Pressure Station Pressure

Humidity

[?]Humidity Relative Humidity

Heading

[?]Direction of Fire The heading to the target as referenced to true north. The direction shuold be entered in number of degrees from North (0 degrees).

Inclination

[?]Inclination This is the uphill or downhill angle to your target and is measured with an inclinometer (angle indicator). The value will be positive for look-up angles, and negative for look-down angles. Small look angles, like less than 5 degrees can typically be ignored with little consequence even for long range shooting. If the angle exceeds 10 degrees it becomes increasingly important to account for.

Latitude

[?]Latitude The latitude position of the shooter on the Earth.

Target Speed

[?]Target Speed The speed of the target movement.

SSF - Elevation

[?]SSF - Elevation Input that describes how much your reticle actually moves in response to a given adjustment. For example, if you dial 40 MOA on your scope and it only really shifts the point of aim by 38.5 MOA, you need to apply a sight scale factor (SSF) to account for this, otherwise your scope adjustments will not result in the proper aim.

SSF - Windage

[?]SSF - Windage Input that describes how much your reticle actually moves in response to a given adjustment. For example, if you dial 40 MOA on your scope and it only really shifts the point of aim by 38.5 MOA, you need to apply a sight scale factor (SSF) to account for this, otherwise your scope adjustments will not result in the proper aim.

Zero Shift - Elevation

[?]Zero Shift - Elevation If your POA does not exactly equal your POI at the zero range, you can enter how much the group is off center. In other words if you have 1/4 MOA clicks on a scope and the zero is 0.1" high, you can enter this here to account for the error that's less than 1 click. Use negative to indicate down, positive for up.

Zero Shift - Windage

[?]Zero Shift - Windage If your POA does not exactly equal your POI at the zero range, you can enter how much the group is off center. In other words if you have 1/4 MOA clicks on a scope and the zero is 0.1" right, you can enter this here to account for the error that's less than 1 click. Use negative to indicate left, positive for right.