Caliber Window

Most caliber data are derived from offical standardization bodies, such as CIP (COMMISSION INTERNATIONALE PERMANENTE POUR L'EPREUVE DES ARMES A FEU PORTATIVES, CIP). Values shown contain maximum and minimum values for physical dimensions and pressueres.

The following input fiels are contained in the caliber window:

• Caliber Selection (first drop down)
  By selecting a caliber from the caliber database, all values will be set to default as providet for the individual caliber. If necessary, the following values can be changed:

• Barrel-Diameter (Groove Diameter)
  This value represents the groove diameter of a rifled barrel in the given diameter according to spec. If your barrel happens to have an out-of-spec / different from average groove diameter, the measured out-of-spec value can be entered here.

• Max. Allowed Pressure
  This value contains the max. pressure specified for the selected caliber. This should not be altered, as the value is used to automatically generate Pmax allowed (and above), Pmax allowed until Pmax-15%, and Pmax-15% until Pmax-25%, and possible warnings in the diagram.

• Effective Crosssection
  The effective cross-section indicates the physically effective cross-sectional area on which the combustion pressure acts on. This value is predetermined by the specification for the caliber. This value depends on the number and construction of the rifling. You can adjust the value to your particular circumstances using the assistant (yellow star), for example, if your barrel has 6 grooves instead of 4.

• Case Length
  Enter here the self-measured length of the cases ready prepared for the reloading process. The value is pre-filled with the maximum case length according to the official caliber specification. This value needs regularly to be replaced by own measures of the reloader.

• Case Volume
  Enter here the average case volume from a FIRED case. Only, if measured correctly, GRT's simulations will calculate accurate results. This value needs regularly to be replaced by own measures of the reloader.

• Cartridge Length
  Over-All Length (OAL) of the Round. The total length (e.g. “OAL”, or “L6” according to CIP) is the distance between the tip of the bullet and the base of the case of a given cartridge. This value is calculated based on actual case length, the length of the projectile minus the seating depth of the bullet into the mouth of the case.

• Combustion Chamber
  This volume shows the available space, available for powder gases, inside the cardridge with a seated bullet.

• Sebert Factor
  The Sebert factor defines the amount of powder mass flowing together with the bullet through the barrel. Depending on caliber it is a value between 0.1 und 1.0.

• Barrel Length
  The length of the barrel of the gun, the simulation is calculated for. This value needs regularly to be replaced by own measures of the reloader.

• Projectile Path
  The distance, traveled by the projectile, until it leaves the barrel.

• Gun weight
  The gun weight is used for the recoil calculation.

• Twist length
  Die Dralllänge wird für sekundäre Anforderungen verwendet, z.B. einem Bullet-Stability-Plugin, nach Bedarf bearbeiten.

• Gas leakage
  Definition and edit of gas leakages in the guided bullet-path of the barrel, e.g. the cylinder gap of revolvers. Be sure to read the notes in the editing window!