Calculating DSF

Discussion in 'Main Message Board' started by KB0321, Jul 9, 2018.

  1. KB0321

    KB0321

    Joined:
    Jul 9, 2018
    Messages:
    2
    Hey guys
    I am calculating DSF and have been taught to shoot at Rtrans 75%. Going off the transonic range of Mach 1.2 - Mach .8, Mach .9 would be 75% of the way through the transonic range. The Kestrel instruction manual concurs with this and suggests shooting at a range where your remaining velocity is Mach .9.

    However, the measurement in my kestrel 4500NV model for rtrans75% is higher than Mach 1. It seems to be measuring 75% on a transonic range of Mach 1.2 - Mach 1.

    From what I understand:
    -True MV at Mach 1.2
    -Refine your BC at 75% through transonic range
    -Refine again your BC at Mach .8

    Is Rtrans75% measuring a transonic range of Mach 1.2 - Mach .8 or Mach 1.2 - Mach 1?

    Thanks for the help
     
  2. corsair4360

    corsair4360 Silver $$ Contributor

    Joined:
    May 25, 2008
    Messages:
    18
    What do you mean by the term "DSF" in your question?
     
  3. KB0321

    KB0321

    Joined:
    Jul 9, 2018
    Messages:
    2
    Drop/Drag Scale Factor. Truing your ballistic coefficient to the trans/subsonic ranges.
     

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