Tikka T3X

Discussion in 'Reloading' started by GW Hunter, May 19, 2018.


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  1. GW Hunter

    GW Hunter Well-Known Member

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    May 2, 2015
    Reloading my nephew's Tikka T3X in 300 win mag. Once fired cases measure 2.273" and chamber like butter. No tension at all, with a stripped bolt (no firing pin or ejector button). Ran one through the die while using a .010 Redding comp shellholder (least affecting) and the case actually grew to 2.275". It still chambered with no resistance. Is this normal for a chamber to be so "loose"? Anyone have similar experience with a Tikka having a chamber like this?
     
  2. bigedp51

    bigedp51 Well-Known Member

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    By your measurement the full length sized case grew .002 with the +.010 competition shell holder.
    Try the +.008 competition shell holder and see if the case becomes longer.
    Keep going with shorter +.006, +.004 etc shell holder to see where the shoulder moves.
    You may have to fire the case several times and only neck size until the case becomes long enough to cause effort closing the bolt.

    Below your case "MAY" become longer if you size the case more and reduce the case diameter more. This depends on your chamber and dies, example a fat chamber and skinny die will make the case grow in length more.

    [​IMG]

    The case shoulder location on new rimmed and belted cases is not critical because the case does not headspace on its shoulder.

    Below a new .303 British case in a Wilson case gauge and this case is still not resting on its shoulder. And the rim is stopping the case from dropping further into the gauge, and the case shoulder was actually 1/4 shorter than the chambers shoulder.

    [​IMG]

    And below is a fired case in the Wilson case gauge and the amount the case is sticking above the gauge is how much longer the British .303 Enfield chamber is.

    [​IMG]

    The British used cordite powder that looked like long strands of spaghetti. And the powder was loaded into the rimmed and belted cases "BEFORE" the case shoulder and neck were formed. So the case shoulder location was not critical if shorter than the chamber.

    Below a new and old rimmed .450 Martini cases, and you can see how crudely made the older case on the right is. Bottom line the belted case is a old British design and even today the cases can be much shorter than the chamber.

    [​IMG]
     
    Last edited: May 19, 2018
  3. GW Hunter

    GW Hunter Well-Known Member

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    Using the next step shellholders in the set would eventually push the shoulder back which is not what I'm looking to do. I was just surprised to see that the chamber is as long as it is. I'm guessing this would reduce the life of cases fired in this rifle...
     
  4. bigedp51

    bigedp51 Well-Known Member

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    Dec 10, 2010
    What I'm getting at is the more you squeeze the case the more it will grow when full length resized.
    What I wanted you to do is try the +.008, +.006 competition shell holders and see if the case grows or becomes shorter.

    Also if you just neck size a few times you will find the maximum case shoulder growth. And find the "true" chamber shoulder length.

    Below on the left a new unfired rimmed .303 British case and the much shorter shoulder location. In the middle is a once fired case and on the left is a case full length resized twice. The case on the right started to separate because the case was full length resized. And if the case had minimum shoulder bump with the case headspacing on its shoulder it would not have stretched and thinned. The chamber was tighter than the GO gauge but the cases had thin rims and had .009 head clearance. Meaning the case stretched .009 each time it was fired and this was beyond the elastic limits of these Winchester cases.

    [​IMG]

    The secret to rimmed and belted cases is to forget the rim and belt and let the case headspace on its shoulder. Chambers and dies vary in size. And sometimes you are forced to neck size only with long fat chambers when you have short skinny dies.

    [​IMG]

    [​IMG]
     
    Last edited: May 20, 2018
    therifleman556 and 7stwnut like this.
  5. GW Hunter

    GW Hunter Well-Known Member

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    May 2, 2015
    Tried what you suggested. The case didn't change with the .08 but the shoulder did get pushed back .02 with the .06 shellholder. I will also go with your suggestion of neck sizing to get the cases to grow to chamber length. Makes sense....