Casting minies became puzzling

Discussion in 'Handloading and Reloading' started by Jeff62, Aug 6, 2022.

  1. Jeff62

    Jeff62 Member

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    Im home brewing for a new to me Parker-Hale 1858 Enfield 2 band.
    I ordered a 575-500 Lee mold and started casting today with some roof flashing scrap that thumbnail tests soft. Also, I got my new Lee Pro lead melter yesterday so I used that to melt. I have always used a cast iron pot and ladle up to now. This was eye opening.

    Results are of a hundred bullets about a dozen have a void in the skirt. Strangely the bullet in the photo depicting the void weighed 33.8 grams while the smooth bullet weighed 33.5 grams (521 grains @)
    Both measure .577 straight from the mold. Neither bullet was wrinkled as if from a cold pour.
    I don’t think I’ll reject the void bullets but any ideas on avoiding that result are appreciated.
    Lead pot tips are apropos as well. E1E796F7-F6B3-4430-A48F-A42D3A4A600F.jpeg
     
  2. Slamfire

    Slamfire Member

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    I talked to Ray Rapine, who was a mold maker, particularly for old historic firearms. I have a couple of his Minie ball molds. As Ray told me, when casting 500 grain bullets, you have to get the lead hot! I forget how much more hot than 30 caliber bullets, but it was a lot hotter. Just keep on casting, eventually you will get the mold release just right, the casting temperature right, and the pour process right.
     
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  3. Thomasss

    Thomasss Member

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    If you can find the spot of the void in your mould, wash it real good with an old tooth brush and mineral spirits. Dry it out good and smoke the mould with a real bees wax candle if possible. Slamfire is correct to tell you to get your lead nice and hot. Have you ever seen castings get a frosty finish. That is the hot you are looking for.
    I don't know how you pour, but another trick is to pour the lead until it fills the sprue and then falls off and over the outside of the mould before stop pouring.
    Moulds will pull additional hot lead into themselves as the inside cools a little. And with big bullet casting, give 'em all they can take even if it gets a little messy.
     
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  4. Jeff62

    Jeff62 Member

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    You are both making the point that I considered first. My lack of experience with the electric pot may well be the culprit. I melted my ingots on high and backed it down to @41/2.
    As to the frosting of a bullet; if I saw that my first response would be to cool it down a bit. For the past twenty years I have been casting out of a cast iron pot on my coal forge. A moment of inattention and I have overheated my lead making yellow crystals, very bad stuff. I’ll keep your advice in mind Thomass.
     
  5. brewer12345

    brewer12345 Member

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    Get a lead thermometer. Much, much easier to see what is going on and get repeatable results.
     
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  6. AJC1

    AJC1 Member

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    I must be the only caster that has never casted a frosted bullet. I'm guessing that it's easier with big bullets. When I run out of my dad's 45-70 bullets. I test just to see what it takes.
     
  7. 243winxb

    243winxb Member

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    Only 12 bad ones. That ok.

    The biggest i cast was 1 oz Lee slug. You might try pressure casting. Bottom pour spout in contact with the sprue plate. I use a Lee 10 pound pot.

    Be very careful, if trying pressure casting. Hot lead can spray out at you. Maybe even more with a 20 pound pot?

    More heat may help, but frosted in Lee molds can make voids, as the cooling bullets pulls away from the side of the mold.

    Getting the lead into the mold faster some times helps. A saeco iron mold in 38/158 gr need the sprue hole slightly bigger, as did the hole in the bottom pour spout.
     
  8. Random 8

    Random 8 Member

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    I'm not a bullet casting expert, but I do cast a lot of fishing sinkers in the 1 to 2 oz range. In addition to proper hot alloy, smoking and preheat of the mold are critical. I use a paraffin candle for both smoking and fluxing. When all else fails, a little tin alloy solder helps things fill without adding significant hardness.
     
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  9. AJC1

    AJC1 Member

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    Tin is a great idea for fill out, I don't cast black powder or shotgun so I hesitated to recommend it.
     
  10. PRD1

    PRD1 Member

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    My experience with Minie molds and pure lead is that you need to get the metal hotter than most electric furnaces are capable of. Even with lead at 850 degrees F., you get many casts with voids at the bottom of the base cavity, because the base plug cools faster than the mold blocks. And even when the void is not visible, weighing the bullets will show wide variations in them, due to hidden voids. Pure lead for Minies (and they should always be of pure or essentially unalloyed lead) needs to be HOT in order to produce properly cast Minies of full weight.

    PRD1 - mhb - MIke
     
  11. Jeff62

    Jeff62 Member

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    I’ve taken notes. I thank y’all for your considérate responses
     
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  12. MEHavey

    MEHavey Member

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    N-SSA'r experience

    Pure Lead: 800° (Trust me:))
    Minnie Balls: Do not contact pour. Free pour from a quarter inch above sprue plate and allow the lead to puddle*

    *You need that air release to prevent base voids in the Minnie's deep/hollow base
    (ask me how I know :fire:)

    .
     
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  13. lightman

    lightman Member

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    I consider myself to be an experienced caster but the first time I tried casting hollow base minnies was a challenge!
     
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