Trim Length

Discussion in 'Reloading' started by Jinx-), Apr 22, 2010.

  1. Jinx-)

    Jinx-) Well-Known Member

    Messages:
    693
    Joined:
    Aug 23, 2009
    Reading an article
    Precision Hand Loading for Long Range-Chapter One: Brass Sort & PrepBy Tres MonCeret

    in the part where he talks about Trim to Length
    Precision Hand Loading For Long Range-Chapter One: Brass Sort & Prep
    the Sinclair Chamber Length Gage was used to determine the chamber length
    Case Gauges & Headspace Tools - Sinclair Chamber Length Gage

    Then Tres recommend to "trim your brass just short of this measurement instead of “book trim to” specs."
    the part I don't get it, how short is short, do I need to be few thousands or hundreds off from the max?

    Thank you.
     
    Last edited: Apr 22, 2010
  2. Jinx-)

    Jinx-) Well-Known Member

    Messages:
    693
    Joined:
    Aug 23, 2009
    Upps I will ask Tres directly :D
     

  3. Jinx-)

    Jinx-) Well-Known Member

    Messages:
    693
    Joined:
    Aug 23, 2009
    no response yet from Tres, but I'll go ahead and ask you guys :D I trim 0.005" shorter them actual chamber length do you think I should cut lower or not?
     
  4. GNERGY

    GNERGY Guest

    I usually trim .015

    Tarey
     
  5. Jinx-)

    Jinx-) Well-Known Member

    Messages:
    693
    Joined:
    Aug 23, 2009
    Is there a proven rule to go by when it comes to triming, maybe some formula something I can plug in to get best optimal length for my brass to fit in my chamber?:rolleyes:
     
  6. Gene

    Gene Well-Known Member

    Messages:
    1,326
    Joined:
    Jan 23, 2007
    It is not a good idea to use factory or SAMMI spec lengths, as the end of the loaded case could contact the end of the barrel chamber, depending on how it was cut. This could cause pressures to skyrocket, not a good thing. For that reason, most reloaders trim between .010" and .020" below the SAMMI lengths. There is no good reason to do otherwise.
     
  7. trueblue

    trueblue Well-Known Member

    Messages:
    2,127
    Joined:
    Feb 18, 2008
    trim 0.020 off
     
  8. Jinx-)

    Jinx-) Well-Known Member

    Messages:
    693
    Joined:
    Aug 23, 2009
    All right then, lets try .223 as an example, with Sinclair tool it measured 1.775" as my chamber max, SAMMI has trim length 1.750" when 1.760" is max, so trim is 0.010" from max, so should I also cut 0.010" to 1.765 or 0.020" to 1.755"?