Lines in Cast?

rdinatal

rdinatal

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I cast some 45/70 405gr over the weekend in a double cavity. The first few sets came out fugly. As I continued it was better but not great. There are lines in the bullet. What's the cause?

I'm thinking that the lead is not hot enough causing cooling before the cavity is full.
If so, what is a good temp?
(I have an IR thermometer)

Can it be too hot?
 
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My limited experience suggests that you heat the lead to around 750 or slightly above and keep casting rejects until the mold gets hot enough. Put the rejects back into the pot. The bullets will start getting a bit frosty if you get things much hotter. I do not think the frostiness hurts anything.
 
Cold molds and cool lead are the two most common problems for lines in the bullet.
 
I did the same this weekend, with a new Lee mold. One side would not take smoke. I'm sure if I cleaned it first it would have worked better. But 30 rejects and more attempts at smoking it got it working.
 
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Your lead and or molds are too cool. Get the lead temp to about 700-750. I usually lay my mold on top of the pot slightly opened to get it up to temp and most times my first drop is good bullets. Like others said, take a lighter and get your molds good and sooty.
 
rdinatal said:
I cast some 45/70 405gr over the weekend in a double cavity. The first few sets came out fugly. As I continued it was better but not great. There are lines in the bullet. What's the cause?

I'm thinking that the lead is not hot enough causing cooling before the cavity is full.
If so, what is a good temp?
(I have an IR thermometer)

Can it be too hot?
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Soot your cavities with a cheap butane lighter. Get the lead good and hot. I’d say 750+ for 1 or 2 cav molds and a tad hotter for 4-6 cavities or shot molds. Heat the mold hot before starting and once you start roll hard. When the lead sprue takes 7-10 seconds to cool then your molds getting too hot so go take a short break and refill the pot.
 
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Heat molds, try more tin if possible, Start casting don't even look at first 10 or so bullets throw back in pot, get molds hot if still have lines increase pot temp. 25 to 50 degrees there is a happy temp somewhere. Try some linotype if you find it. It will cast a pretty but hard bullet.
 
You may need a better thermometer. Melting point of lead is around 620 * F.
 
Ditch the IR thermometer and get either a thermocouple one or a mechanical, both measure the actual temp. IR ones can be quite inaccurate.

Past that, either your lead or mold or both are too cold. Regardless of what some folks say, bigger bullets require higher temps and must be poured fast. I regularly cast heavy lead bullets (think 500ish gr) for my Civil War muskets and run my pot at 850F and heat the mold. And no, lead does not vaporize anywhere near that temp. Many of my friends who shoot Civil War guns and myself have entirely normal lead levels. You're more likely to have elevated lead levels from inhalation in an indoor range. Modern center-fire primers have lead styphnate in them and it gets sprayed around with each shot.
 
Set your pot to "8" or higher on the dial. Let the lead heat for at least 45min, start casting. Recharge the pot when about 1/2 empty and wait for it to come back up to temp. Again, the mold must be hot as well. These ain't those dinky 9mm or 45acp bullets.

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Might help to lie the mold across the top of the pot and let them both heat up together.
 
Don’t throw the rejects back in the pot until you’re done casting. It also cools the pot while you’re trying to cast.
 
The hotter you go, the smaller your bullets will be, so watch for that.
IR thermometers are great, but not so much for reflective surfaces, get a proper thermometer.
Oil in the mold cavities can cause lines and wrinkles.
Don’t look at the bullets while casting, you’ll sort them later, for now get into a rhythm that keeps the mold hot.
When the mold starts to get too hot the bullets will start to look frosty and take longer than you want to solidify.
 
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