Cutting a die body shorter?

Discussion in 'Gunsmithing' started by Buttermilk, Feb 25, 2013.

  1. Buttermilk

    Buttermilk Well-Known Member

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    Is it possible to cut a die body shorter by as much as 0.35"-0.40" with out destroying the die?

    What would be the best way to avoid excessive amounts of heat, and thus effecting the heat treatment of the die?

    Thanks.

    Regards,
    Rog
     
  2. dieseldoc

    dieseldoc Well-Known Member

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    Send it to machine shop and have then shorten it on a lathe.
     

  3. J E Custom

    J E Custom Well-Known Member

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    You could grind it using a coolant and not effect the heat treatment.

    I have heard of taking .005 to .0010 of the die body of dies that don,t size quite enough or wont
    bump the shoulder,but not as much as you intend to.

    Are you thinking about wild catting a cartrige by shortning and bumping the shoulder?

    J E CUSTOM
     
  4. bigngreen

    bigngreen Well-Known Member

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    I chucked up one in the lathe last weekend and cut it back .300 for a form die, it took carbide tooling to cut it but with that it cut like butter.
     
  5. Buttermilk

    Buttermilk Well-Known Member

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    I have a 30-338 WM that has a tight chamber. Virgin brass fits and fires just fine.

    Unable to locate 338 WM brass to neck down, I found some 7 RM brass in both R-P and W-W brands. Been necking this up to make the 30-338.

    Once fired brass (7 RM) from my own 7 RM Browning rifle and once fired from the local range will not fit my chamber even when full length resized.

    Inking a case and inserting the case into the chamber as far as it would go revealed where my chamber is snug.

    My chamber is snug on the front end, based on where the ink was rubbed off the case.

    Taking measurements of the cases that don't fit and of virgin brass also confirm that the shoulder area of my chamber is tight.

    Perusing thru my reloading manuals at case drawings leads me to believe I might be able to use a 8mm Rem Mag or 7 STW "body" die modified in length to resize the shoulder area enough to get these once fired cases to fully enter my snug chamber.

    Lee offers a 7STW body die that would need shortened/modified on both ends. An 8mm RM body die shortened enough at the base would likely work better.

    Regards
    Rog
     
  6. phorwath

    phorwath Well-Known Member

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    A grinder and water to keep it cool will work. Won't look as pretty as a lathe cut die, but it will be just as functional if you remove any burrs on the inside edge. Of course, knowing a buddy with a lathe is the superior option. A machine shop will probably soak ya.
     
  7. Trickymissfit

    Trickymissfit Well-Known Member

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    depending on the brand of die, you can chuck it in a lathe and shave the base with a carbide insert or better (I prefer ceramic inserts). It's a good idea to use a spray mist directly ontop the insert to keep the heat out of it. Your probably not going to draw the heat treat back enough to matter with the heat involved anyway, but you absolutely want the heat to be in the chips and not the part. If the chips come off super hot, your about right. You can get this by changing the spindle speed. After you remove the metal to change the length of the die, you will need to cut a very small chamfer and then radius it with some emery cloth followed by the same thing in 400 grit black paper with a little oil on it (I recommend using a small wooden dowl. Thirty thousandths is about right for the radius. Spindle speed will vary with the metal alloy and heat treat, but a good place to start is around 400 rpm with a ceramic insert and then adjust from there. I used to slice A2 drill bushings at 600 rpm all the time with little heat retained in the part.
    gary