alloying question from a learning new caster!

[GBCAPT]

I have about ten pounds of what was called "foundry type" which I melted and cast in a 160 gr 312 mold. The bullets are bright, but have a definite light lavender sort of color and my Lee hardness tester indicates a BN of about 25. I do not intend to shoot these, but rather to use them to improve the characteristics of other alloys I have collected.

I also have about 50lb of 50% range salvage and 50% soft reclaimed lead, which I attempted to cast with this morning. This lead did not fill well and resulted mostly wrinkled bullets no matter what temp I used or how hot I preheated the molds to.

My suspicion is it need a bit more tin.

My next planned move is to blend in some of the foundry type alloy to improve the fill charectristics of my 50lb batch.

The question though is at what rate? My RCBS Pro-melt is about 2/3 full but I don't know what that weighs.

Any and all recommendations from others with more experience than me will be appreciated and duly considered!

[Kosh75287]

Do the 25 BHN projectiles weigh 160gr.? If yes, then they are about 0.37 oz. each. They are probably not PURE tin, but likely very high in tine content. Add one projectile to your melt, mix thouroughly, and try casting. If the mix doesn't fill out the mold, return it to the melt, with another bullet, and repeat. Keep count of how many bullets you add, so you'll have some sense of the proportion needed in future casting.

[runfiverun]

foundry type was used to rejuvenate linotype.
it's something like 9% tin airc.
try a pound of it to what's in your pot now and see what happens, if it's better but not good add another 1/2 lb.

[454PB]

You can do some math and come fairly close......but it's probably as fast and easy to do what R5R said. Foundry type is supposed to be 15% tin, 23% antimony, and 62% lead. If your RCBS pot is 2/3 full, call it 15 pounds, or dump it out and start over.

[bumpo628]

Download my alloy calculator (see link below) and then you can play around with the percentages until you find the mix you're looking for.

[Oklahoma Rebel]

what temp was your alloy when you got the wrinkled boolits?

[Lloyd Smale]

first thing I would do is turn up the heat and try to get good bullets with what you have. It would be a shame to dump good foundry type in a pot of contaminated lead. If it turns out to be good lead then id about about 10 percent by weight of your foundry type and try casting again at a lower temp. Bottom line is theres absolutely no reason why you cant get perfect cast bullets with pure lead with no tin or antimony in it if you have the heat at the right level.

[RogerDat]

Download my alloy calculator (see link below) and then you can play around with the percentages until you find the mix you're looking for.

Get the alloy calculator! Free and a great tool. You know what you have at least roughly. Foundry type, berm lead, soft plain lead. Plugging different amounts of those alloys into the alloy calculator will get you very close to a precise alloy you desire, and is repeatable using slightly different raw ingredients in the future.

Too cold or solvent oils in the mold are generally causes for "smiling" wrinkly bullets. They often have a single curved wrinkle that is sort of like a smile in the side of the bullet. I clean molds with brake clean, followed by dish soap and water with a tooth brush, good hot rinse and blow dry. Less than that I seem to get at least a few wrinkled ones until the residue of some oil, soap , or solvent burns off.

Get a thermometer if you don't have one this one measure to 1000* and is inexpensive. https://www.amazon.com/Tel-Tru-LT225R-Replacement-Thermometer-degrees/dp/B0055777EU Even if not exactly precise temperature reading they are a repeatable one, you find the temperature your alloy cast well in a specific bullet mold you can make a note of it and repeat as needed. Lyman also makes one that is more expensive.

You can always just keep adding sweetener until it works but that presumes the lack of alloy is the problem, wrinkles are not always caused by alloy issue. Temp too low and boiling off of residue is more common.