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SwedeNelson
Glen Fryxell full length book on bullet casting, a must read for any bullet caster and reloader.
The foreword is by John Taffin and says it all about this book.From Ingot To Target, A cast Bullet Guide For Handgunners (In html)
From Ingot To Target, A Cast Bullet Guide For Handgunners (In pdf)I’m sure you’ll enjoy Glen’s writing and find as much good solid information in it as I did.
Bullet maker, maker
Al Nelson
SwedeNelson-
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ringo10x
AlvinYork
In case anyone’s still wondering, I’ll define the terms as far as I understand them
Eutectic – this means that, after the correct temperature is obtained and kept at that temperature or below, all the elements of your alloy are combined and cannot be separated. So the notion that you have to stir your alloy is incorrect . . . as long as it’s not above the proper temperature. When your temperature goes too high that’s when things literally come apart. The first thing I usually notice is all my tin floating on top of the melt. And at that point stirring actually won’t help, you’ll need to drop the temperature to regain your eutectic state.
Precipitation – The example I gave of my tin floating on the surface of my melt is due to the lead and antimony “precipitating”, just like rain from the clouds, downward into layers based on their weight. So the lead will precipitate to the bottom of the pot, the antimony on top of that and the tin on top. My tin clumps together like a mini iceberg and travels around the pot. To word it the way Fryxell does : The lead precipitate is at the bottom of the pot, the antimony precipitate settles on top of that and the tin precipitate floats on the surface of the melt.
tertiary – I’ve got to go back and see how he uses this word. . .
Hope this helps.
bradtrojanowski
Eutectic-relating to or denoting a mixture of substances (in fixed proportions) that melts and solidifies at a single temperature that is lower than
A Eutectic mix melts at a lower pont than any other combination of the ingredients or the ingredients themself. 63/37 Pb/Sn solder is a good example.
Alvin is kinda speak of a solution vs a mixture. A solution can’t be separated by physical means. Our alloys are solutions. They do NOT gravity separate. At high heats we do loose tin but it is via oxidation, a chemical process. The tin oxide is not soluble and therefore floats as it has a density below that of the alloy.
Alvin s wrong on what is happening in his pot via precipitation. He is speaking of gravity separating which does not happen as we have a solution. Oil and water are a mixture and they do gravity separate. We have the equivalent of salt in water, the salt remains in solution no matter how long it sits.
Precipitation is of concern for us because as the temp drops some of the elements harden faster than others. This is due to the fact the elements in solution have different melt points. Antimony can precipitate out of solution and give a bullet with antimony crystals in them. Adding tin alters this some as the tin and antimony form an intermettalic that remains in solution a bit longer.
A binary alloy has two ingredients, think 20-1 lead -tin
A ternary alloy has 3 ingredients, think lead, tin, antimony.
A tertiary alloy has 4 ingredients, think of adding arsenic to a ternary alloy.FYI- all of this can easily be found via a simple google search.
Please don’t fall into the trap of thinkng a solution, what we are casting with, can gravity separate. It just isn’t possible. Tin separation is a chemical process, not a physical process.
rickkelter
A precipitate occur when the solubility of a substance in the solution is exceeded.
Think of rock candy. We add sugar to boiling water. We use heat to allow more sugar to enter the solution than is possible at room temp. We then let the solution cool and add a small seed crystal. The sugar then precipitates out onto the seed crystal. If we kept the water at boili the sugar would not precipitate out.
Air holds moisture. We all understand humidity. We get rain because updraft a push air heavy with water vapor to altitudes where the temp is far lower. The water precipitates out forming a droplet that falls as rain.
Precipitation can be a huge benefit to us. We can remove some zinc from a lead alloy by lowering the melt to a temp at which zinc is minimally soluble in lead alloy. The zinc will precipitate out and float on the surface where we can remove it. We can’t get rid of all the zinc this way as zinc has a certain level of solubility in lead alloys.
Precipitation is all based on the solubility of a substance in the solution that contains it. For us precipitation is largely concerned with what happens as our alloy hardens in the mould. The alloy does not all harden at the same time. Some alloy constituents precipitate out early and for crystals that will later be included in the bullet after it fully hardens.
Some of the older Lyman cast bullet manuals have excellent discussions on this. The 3rd edition in particular has excellent information.
So the notion that you have to stir your alloy is incorrect . . . as long as it’s not above the proper temperature. When your temperature goes too high that’s when things literally come apart. The first thing I usually notice is all my tin floating on top of the melt. And at that point stirring actually won’t help, you’ll need to drop the temperature to regain your eutectic state.Precipitation – The example I gave of my tin floating on the surface of my melt is due to the lead and antimony “precipitating”, just like rain from the clouds, downward into layers based on their weight. So the lead will precipitate to the bottom of the pot, the antimony on top of that and the tin on top. My tin clumps together like a mini iceberg and travels around the pot. To word it the way Fryxell does : The lead precipitate is at the bottom of the pot, the antimony precipitate settles on top of that and the tin precipitate floats on the surface of the melt.
tertiary – I’ve got to go back and see how he uses this word. . . Hope this helps.
While it may “appear” looking at a pot of molten lead alloy that description is what is occurring but it is completely impossible for that to happen. Gravity separation is a physical impossibility for the constituents of a Pb alloy to so separate. It is as Glen describes in his book and Fred has posted here a chemical process. The Sn you see on top of your melt is oxidized tin, with the lowest melting point of the constituents in a Pb/Sb/Sn alloy it will oxidize first. You are correct that the higher the melt temp both the more and the faster it will oxidize. As a chemical process the oxidized Sn can be reversed back into elemental metal in the alloy with the use of a proper flux, also very well described in the book.
milboltnut
Restrictions (reduced diameter) anywhere inside the cylinder mouth or barrel cause the bullet to be reduced in size. After the bullet leaves the tight spot it is smaller than the remainder of the spinally grooved tube through which it has to travel. The bullet then being smaller than the bore has lost its ability to keep the hot gasses safely sealed behind it. Once this seal is broken, the hot gases are free to rush past the delicate sides of the bullet and act as a circumferential cutting torch blowing liquid alloy ahead of the bullet essentially tinning the bore ahead of the bullet causing even more lead to be wrenched from the already damaged circumference of the bullet. What all this boils down to is severe leading and poor accuracy.
I have a factory Taurus 66 with no modifications.. I ran a oversized cast bullet through the chamber mouth and it was .357. When I shoot 21 BH no leading occurs in the barrel. Of course I have 1K rounds + through it… and I’m supposing that a 4 inch barrel really isn’t that accurate past 25 yards, even at 25 it’s fair.
ringo10x
AlvinYork
victorjones
bradtrojanowski
rickkelter
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