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Thread: Firing pin radius

  1. #1
    Join Date
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    Escondido, Ca via Ohio
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    Firing pin radius

    Anyone have tips on replacing the radius on a firing pin?

    I'm thinking form tool, unless there's a better method.

  2. #2
    Join Date
    Dec 2006
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    Branchville, NJ
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    I spin them in the lathe and use a fine file and a 1/2" x1/2" abrasive stone.

  3. #3
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    For centerfire high pressure rifles you want a flat with a small radius on the edge. That reduces the distance the primer can flow back around the tip. Small but significant.

  4. #4
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    Quote Originally Posted by Dave Tooley View Post
    For centerfire high pressure rifles you want a flat with a small radius on the edge. That reduces the distance the primer can flow back around the tip. Small but significant.
    So, are you saying, no radius with broken edge?

  5. #5
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    Back in the day, someone told me that a proper tip has two radii. A large one at the center and a tighter one at the edge. I think that you would want to do a little more than break the edge but not come back too far down the side. If you do, you will create space in the front of the hole for a crater. Having a radius on the edge of the hole also contributes to this "problem".

  6. #6
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    Quote Originally Posted by Dave Tooley View Post
    For centerfire high pressure rifles you want a flat with a small radius on the edge. That reduces the distance the primer can flow back around the tip. Small but significant.
    That's a great tip, Dave. I never thought of it that way.

    Every Custom Action I own has a firing pin tip with a radiused end. What you said makes a lot of sense.

  7. #7
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    Sep 2003
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    Quote Originally Posted by jackie schmidt View Post
    That's a great tip, Dave. I never thought of it that way.

    Every Custom Action I own has a firing pin tip with a radiused end. What you said makes a lot of sense.
    I got that one from Ed Shilen way back when.

  8. #8
    Join Date
    Oct 2003
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    Chehalis, WA.
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    In Stuart Otteson's book THE BOLT ACTION, Vol. 1 he states, "...primer indention seldom exceeds about .020 in. " (page 279)

    If this is true, it would seem that a firing pin tip that is radiused back no more than .020" to .025" from the very front would be perfect, and provide a nice seal around the firing pin hole.
    This is what I try to achieve on actions I have made for myself, and it seems to work pretty well.

    FWIW

    Steve Kostanich

  9. #9
    Join Date
    Dec 2003
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    washington.........STATE that is.
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    Quote Originally Posted by ab_bentley View Post
    Anyone have tips on replacing the radius on a firing pin?

    I'm thinking form tool, unless there's a better method.
    LISSEN to Tooley

    basically when it comes to bolt action rifles there's GOD, and about 6 other people.

    Dave is one of those 6

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