text: Appendix C
  the line of fire to the line of sight to a given aiming point. In reciprocal laying, the aiming point for the aiming
  circle is the howitzer panoramic telescope.
  C-44. Survey may not be available. To establish directional control and lay units by the orienting angle
  method, the orienting line must be established. Without survey, the orienting line can be established by hasty
  survey techniques. Once the orienting line is established, the steps shown above apply. The OS grid location
  and altitude may be obtained by GPS, map spot or by hasty traverse. If survey data is not available and hasty
  survey is not possible, then the next best method is laying by grid azimuth.
  C-45. In reciprocal laying, the 0-3200 line of one instrument and the 0-3200 line of another instrument are
  laid parallel.
  ACCURATE WEAPON AND AMMUNITION INFORMATION
  C-46. Accurate weapons and munitions information is developed and provided by firing units, FDCs, and
  sustainment cells. The weapon information is normally applied automatically using the AFATDS. If the
  AFATDS is not functioning the procedures to apply weapons information manually is found in the applicable
  technical manuals and tabular firing tables. Firing tables and technical gunnery procedures allow the unit to
  consider specific ammunition information as follows:
  * Weight of the projectile.
  * Type of fuze used.
  * Muzzle velocity variations.
  * Propellant temperature.
  C-47. Weight of the projectile affects how far or short the round will travel. If the round is heavier than
  standard it will have a decreased range, the opposite is also true if the round is lighter than standard it will
  have an increased range. Compensation for projectile weight is found in the appropriate tabular firing table
  that is being used.
  C-48. The type of fuze will determine the information that is set for the fuze. For a point detonating fuze no
  information is set on the fuze and the round will function as it hits a solid target. Variable time fuze can set
  function at 7 m above the ground by setting the fuze for the appropriate range to be used. Time fuzes can be
  set at various heights above the ground to have better effects against soft targets, such as dismounted infantry,
  radars, C2 systems, or fuel points. All these fuzes require different settings based on their type, function, and
  ranges to be used.
  C-49. Muzzle velocity variation is the difference from a standard speed the round departs the barrel with. If
  the round is traveling faster than the standard speed it will have an increased range, the inverse is also true if
  the round is traveling slower when it leaves the barrel it will have a decreased range from standard. We
  measure this with the M90 chronograph or the M94 muzzle velocity system using the appropriate technical
  manual. While it is not practical to predict (within ±0.1 m a second) the velocity of every round, it is possible
  to approximate velocities to within ±1 or ±2 m a second with current available information. This may be
  useful when calibration is not possible, when updating calibration data, or when trying to increase the
  accuracy of inferred muzzle velocity techniques. When calibration is not possible, the shooting strength of
  the howitzer can be used as the muzzle velocity variation. While this may be enough when no other data are
  available, it is important to understand that a muzzle velocity variation consists of more than just shooting
  strength. An equation can be created for determining a muzzle velocity variation by using its basic parts. In
  the event the muzzle velocity system becomes inoperable the unit can register or extract powder efficiency
  data from another system to apply to the inoperable muzzle velocity system weapon's shooting strength data.
  C-50. Propellant temperature affects the range a round will travel. Propellant has a standard temperature
  based on 70 degrees Fahrenheit. If the propellant is colder than standard the round will have a decreased
  range, if the propellant is warmer than standard the round will have an increased range to the target. A
  propellant is a low-order explosive that burns rather than detonates (TC 3-09.81). In artillery weapons using
  separate-loading ammunition, the propellant burns within a chamber formed by the obturator spindle
  assembly, powder chamber, rotating band, and base of the projectile. For cannons using semi-fixed
  ammunition, the chamber is formed by the shell casing and the base of the projectile. When the propellant is
  ignited by the primer, the burning propellant generates gases. When these gases develop enough pressure to