2 Questions, Temp vs size. & Gray vs silver lead.

[Texxut]

1. Is there some guide/ correlation between temp and "as cast" size?

2. Why is old lead gray and the stuff I cast silver?

[badbob454]

i will try # 2 old lead oxidizes and turns gray new cast lead hasn't had a chance to oxidize yet ..

a guess ... i think the hotter a mold is , the larger it gets ,and thus creates a larger cavity making a larger diameter boolit ..... also some lead- tin- antimony- alloys will shrink more or less than others depending on the mix

[blaser.306]

i will try # 2 old lead oxidizes and turns gray new cast lead hasn't had a chance to oxidize yet ..

a guess ... i think the hotter a mold is , the larger it gets ,and thus creates a larger cavity making a larger diameter boolit ..... also some lead- tin- antimony- alloys will shrink more or less than others depending on the mix

If I remember correctly the above statement is only partialy correct, The hotter that you cast your mould "alloy" the smaller a boolit will drop from it . The lead has a high thermal expantion and will shrink on cooling , this is why the boolits fall from a mould better if left to cool a second or so longer before trying to knock them loose right away. I am sure that those with more knowledge of the properties of the alloy's will chime in shortly as this is my opinion and should be taken with a grain of salt!

[blaser.306]

If you can find a copy of the RCBS cast hand book there is a chart in there that gives some rough outlines on what to expect as far as alloy shrinkage with different mixes.

[cbrick]

Welcome to CastBoolits Texxut,

Antimony (Sb) shrinks less upon cooling than does lead and so will produce a slightly larger boolit, the hotter you cast the more lead will shrink upon cooling and so produce a slightly smaller boolit.

badbob is correct, lead will oxidize and turn a dull grey, when you melt it it hasn't yet oxidized. Higher tin & Sb alloys will show somewhat less oxidation when aging depending on the percentages.

Here's some links that will give the info you asked about.

Cast Bullet Notes (http://www.lasc.us/CastBulletNotes.htm)

From Ingot To Target (http://www.lasc.us/Fryxell_Book_textonly2.pdf)

Rick

[Texxut]

I'll read those links and see if I can find the RCBS book.
The gray/ silver makes sense now,
Thanks guys.

[evan price]

What I've found is- the purer the lead, the more silver the ingots, and pure lead looks like chrome. However the purer the lead, the quicker it oxidizes and turns grey-greenish. Antimony/tin alloys look sort of matte dull silver but they stay more that color, even when its been wet, for longer.

[Texxut]

Thanks Evan. I went to the range yesterday to test some loads I'm working up for a 1911 and took along the BP pistol. I had forgotten what a mess those things are, but it was fun.