Hidden voids in castings

[303Guy]

That cat sneeze, was that into sand? That velocity?

Yes it was into sand. The sand itself is a special quality being very fine and soft. It gets pulverized by the continuous impacts. The surprizing thing was the penetration that little expanded boolit had in it.

Velocity unknown. Howerver, I do have a Chrony and since the cat sneeze load is, well, cat sneeze, I shall be setting up for a little bit of chronographing in my shed! (But don't tell my neighbors! )

The antimony content is likely to be very low but not absent. I have a few samples of different alloys that did amazing things that I would like to get analized. I had one alloy that would cast a hard base and soft nose - the nose portion was actually frosted. Expansion into wet rags stopped at the interface. (The mold has a differential cooling rate by design to prevent voids from forming as it's a nose pour. The idea was that the hot mold would cool from bottom up with the sprue puddle freezing last so as to feed metal into the contracting boolit core. It worked.)

[kbstenberg]

Could i ask several more questions that pertain to related aspects?
Is it easier using a 1 or 2 cavity mold rather than a mold of 4 or more cavities? I would imagine using the smaller molds during the learning stages, then progressing to the larger molds.
Do the bullets molded with the faster/ hotter molds produce frostier bullets or even bullets that have a galvanized appearance?
What other subjects are to be considered that aid for a more consistent cast bullet
An thank you Babore for explaining an re-explaining till it finally sunk in to this thick Mellon. Being new i am up to learning anything that will help. Not to brag. This Summer iv shot 5 or 6oo rounds of 44 mag & 30/30 ( which is a lot for me). An because of what Ive learned here. I haven't had to de-lead either of the guns i have been shooting. All due to the Cast Boolit website.

[leftiye]

Dannix, To be honest Ba Bore was the one who told me how to alloy copper into lead. I think that 303 has taken it to the next level maybe. It may be possible to simply drop the correct amount of copper into solder containing the right amount of tin for the batch to be made, and maybe it'll just dissolve as 303 described. As for the 18 bhn alloy (89% leaad, 10%tin, 1% copper) being too hard, make an X boolit out of it maybe. It should hold together extremely well. Or, paper patch your hollow point and shoot it at 2500 fps.

Someone else here previously - and my ALS prevents me from remembering just who - did a quite scientific stuudy of toughness and his results were that the percent of antimony that produced the best toughness was about 2%. When augmented with tin, that was best at 2% also (IIRC).

And again, it is very workable to accurately, and easily control mold temperature by means of an electric mold heater worked into your sequence. Not that it is good, but it is possible to cast frosted boolits with alloy that is cooler than 600 degrees. Or even get the mold so hot that you can pour the alloy back out of the mold - even after a considerable wait. The point being that if you use an IR thermometer to determine your mold temp, you can determine BaBore's ideal temp and hold it.

[303Guy]

Someone else here previously - and my ALS prevents me from remembering just who - did a quite scientific stuudy of toughness and his results were that the percent of antimony that produced the best toughness was about 2%. When augmented with tin, that was best at 2% also (IIRC).

Now I'm intested! Anyone remember who it might have been or the threat it might be in?

Those percentages and toughness assesment kinda ring true from what I have played around with before - just at a guess but I could be way off.

[lwknight]

I had done some testing with paper patching soft lead for my 44mag and when I used 2.5% tin the result was 99.9% weight retention and an inside out mushroom. You have seen this pictures before.


I never had a "J word" bullet do any better.

[Dannix]

leftiye, I thought it was 5% and 5%, not 2% and 2%? I think it's in the stickies.

Nice boolits lwknight!

[Cherokee]

Good info here, keep it coming....

[Dannix]

I came across this thread today and after doing some re-reading decided to give it a bump for others.

[degruix]

Thank you Dannix, I have printed out part of this thread to insure the information will not be lost.

[Iron Mike Golf]

Good info. As I learn more and get more experience, re-reading things is a real benefit, because I understand it better.

Regarding Sb, Sn and toughness, the idea I caught from that thread was keeping those at 1:1 to each other in increasing increases toughness a lot when water cooled or heat treated. Additional Sb above that may increase hardness but at the loss of toughness.