Casting is Reloading on Steroids
Some general observations that have worked remarkably well for me AND which are supported by NRA research and articles of many years ago ...
Ideally, casting a bullet that doesn't need to be sized avoids 2 pitfalls: sizing softens bullets by destroying the hardened "grain" of the outer surface, and ... it adds an extra, tedious step. I've had very good luck with the following general approach:
Lee Aluminum 2 cavity molds
Cast HOT. Hot enough that the bullets have the satin/frosty finish we're told to avoid.
Drop the bullets into water from the mold. This hardens them well beyond letting them air cool. Be certain to do this in a way that NO water, not even a drop, can splash into the lead pot. Water into a pot of molten lead will EXPLODE!!! Some guys put the water tub in back of them and turn around each time. I put it under the casting area in a way that would contain any splashes. It's much faster that way.
A secondary benefit to casting hot is a synergy of: Hot mold=softer sprues=faster cycling time=nominally smaller bullets. But you have to maintain that speed or the mold cools, the sprues harden, and your cyclic rate plummets. I wear asbestos gloves on both hands and begin by casting pairs of "warmup" bullets as fast as I can. This is to build up the heat in the mold until the bullets get the frosty look that tells me they are hot enough to start water quenching them. The first small batch of warmup bullets go back into the lead pot. It can be done with with one 10 lb. pot, but 2 is better for speed. Cast with one while the other is building up a temperature of 750 degrees or more. When one is half empty, add lead to it and switch to the full, hotter one. Then keep alternating. Casting that hot DOES degrade the tin in your alloy, so you need to pay continual attention to how your bullets are filling out their molds and add tin accordingly.
Because of the water quenching, you are not so dependent on alloy for hardness. You won't need to fiddle with adding antimony. Add tin only sparingly to improve the "castability" if you notice the bullets aren't filling out well. Tin is most readily available as bar solder from a hardware or automotive outfit. If you add too much tin, your alloy will begin to act like solder. It will look very shiny and smear all over the mold blocks and sprue plate and will be a major PITA. Remedy by adding more lead or wheel weights to even out the ratio of lead to tin.
Contrary to oft-repeated misinformation, wheel weights are the nearly perfect alloy just as they are. If your bullets are coming out larger than you'd like, add a little lead to the alloy to bring the size down a little.
With the Lee molds, I've found that .40, .44 & .45 all throw a nearly pefect slug right out of the mold. Tumble lube these with the liquid alox lube and life is sweet. My Lyman lubrisizer now only gets used to put gas checks on rifle bullets. With the smaller calibers like 9mm and .38/.357, it's a little tougher to get the as-cast diameter right out of the mold, but it can be done with a little trial and error. As mentioned above, the closer to pure lead your alloy, the smaller your bullets, AND the hotter your mold, the smaller your bullets. So ... plenty of room for tweaking, adjusting and fine tuning.
I have found it easier and more streamlined to cast wheel weights into ingots in one session and ingots into bullets in a different session. This owing to the somewhat dirty condition of wheel weights when we first obtain them. Some guys tumble them in kerosene and sand to clean them up first, though I haven't tried that yet. Wheel weights are usually greasy and smoky when first melted and ideally this step will be done outside. Instead of a furnace, I use a campstove and a large, Wok-like pan, both obtained at garage sales. This is so much better for working with large quantities of wheel weights. Once melted, the little clips and other contaminants need to be skimmed of the top. After that, it's usually a good idea to stir in some flux to float the other crud to the top and skim that off as well. If you don't have an ingot mold, you can ladle the alloy into muffin tins, angle iron, or anything that will form something wieldy once the lead has cooled, which is almost instantly.
All of this advice is general and some fine tuning is certain to be necessary. I know that I've gone against some conventional wisdom, but I've derived a lot of benefit by being willing to try things that are a little out of the ordinary. If you're even just a liitle bit crafty about obtaining used wheel weights from gas stations and tire shops, you can cast bullets for next to nothing.
Feel free to ask questions.
