Bullet Casting: A (Relatively) Simple Introduction, by AVL

Bullet casting is likely one of the oldest activities regarding firearms. From the time humans graduated from using shaped rocks, casting was the method of choice for just about every projectile. While there are other methods that allow for more complex designs (swaging, see corbins.com) casting is still the best simple method for turning a lump of otherwise useless lead into a projectile that will put food on your table and protect your family.
Safety
It is important to note that casting is a dangerous process. Casting will expose you to toxic metals at high temperature. Safety is paramount. I suggest wearing safety glasses at the minimum. At the max, wear a welder’s apron or suit, with the boot covers, a face shield, hat, and respirator (rated for metallic oxide gasses). Molten lead flows like water, but with the density of concrete and will either sear, or vaporize anything it comes in contact with including but not limited to human flesh. Have a fire extinguisher near by, as well as a large tub of water (if you get splashed, immediately immerse the burn area in cool water). Conduct all casting outside, or in a very well ventilated area. I typically work on the back porch, with a box fan blowing vapors away from the house and myself. I most often set the melting pot on the [porch] floor; so if it spills it will not splash everywhere. When casting, melt lead only in steel or cast iron containers, aluminum will not stand up to the heat, neither will zinc, or copper.
Tools
The beauty of bullet casting is it's a simple process, however, without the right tools it is impossible. This section covers the tools you need to make a bullet. I will discuss reloading in a future article (I'm still working on it).
Heat Source
The heat source can be anything, from a campfire, to a camp stove, to a blowtorch. The heat source I have chosen is a dual fuel stove made by Coleman. It is small, has a single burner, and is powered by gasoline or camp fuel. The thing to keep in mind is the more BTUs a stove can put out, the more lead you can melt. One of those large Cajun cookers used for turkey frying kits is ideal. It has a sturdy base, hooks up to a bulk propane tank, and will boil 5 gallons of oil in nothing flat.
Melting Pot
The melting pot is another thing that can be improvised from whatever you have available. Generally speaking you want a metal pot that is somewhat shallow <5" and rather wide 8" or so. I use a 2qt Texsport Dutch oven I bought for $10 at a local surplus store. This pot reliably holds about 40 lbs of lead, has a lid which makes it great for breaking down large amounts of scrap (the lid helps pre-heat all of the material, so it melts faster.). I recommend owning several of varying sizes, large laboratory crucibles work, I also used a 20oz steel coffee cup for a while, and still use this when the lead gets too shallow in the big pot.
Lead Handling Tools
There are a number of tools, which are useful for this. I recommend several pairs of slide-lock pliers; they are great for handling hot flasks of lead that otherwise you couldn't pick up. You should also have several pairs of gloves. A set of welding gloves is great, as well as a set of heavy gardening gloves for sorting scrap lead; they will also protect your hands from the heat when the welding gloves are too cumbersome. Additionally, a few hooked tools (for picking up the lid, and the lead pot) come in handy. Also you will need a large ladle, a large stainless steel ladle is good for pouring lead into ingot moulds. The final tool that is an absolute necessity is the ladle for pouring lead into the bullet moulds. These are typically fairly small, and only hold about an ounce or so of lead. I recommend buying a ladle purpose made for this (the one made by lee manufacturing is cheap and works great. I recommend buying several ladles for when your friends want to try. If you have several mould sets, you can cast out 20 lbs of lead in nothing flat with help).
Bullet Moulds
The bullet moulds are probably the most important part of your casting setup. Without these you don't make bullets. I recommend lee moulds for starters, they are inexpensive, and for low volume production fit the bill, they also heat up quickly due to their aluminum construction and are ready to cast with 1-2 heat pours. A good place to buy moulds is at gun shows. There are a number of people who frequent these shows who seem to be locked into a serious casting hobby, and have great numbers of used moulds for sale at reasonable prices. Most of the people who are really into bullet casting buy Lyman moulds almost exclusively, and I have found that they have a great variety of cavity shapes that will fit almost any bullet makers want list. Most bullet moulds also need a knocker or a mallet for cutting the sprue off. I use a length of hanger rod (wooden) about 12" long. Others recommend hammer handles (no head, just handle).
Ingot Moulds
If you are interested in casting, you should buy at least one ingot mould. Ingot moulds allow you to break down large volumes of scrap lead, and put it into a form, which can be saved for later use. Most ingot moulds cast one pound blocks. This is by far the most useful size unless you are doing small batches of test alloys. Lee makes an ingot mould that makes 2 one pound bars, and 2 half pound bars, I personally prefer the Lyman mould, which makes 4 one pound bars.
Hardness Tester
Hardness testers will measure the hardness of a given alloy and are useful if you are trying to make bullets with certain characteristics. Most hardness testers measure lead hardness on the Brinel scale, and it is possible to adjust the alloy while it is still molten. If you wish to do this, you should have stocks of tin, antimony and pure lead. (Pure lead makes things soft, antimony makes sure the bullets will not shrink too much, tin makes it harder, arsenic can also be used but tin is less toxic).
Lubricants and Sizers
One practice most reloaders are not familiar with when it comes to reloading is lubricating and sizing, All cast bullets must be lubed, and in most cases they must be sized to make sure they are not over bore size. Most mould makers cut their mould cavities larger to account for bullet shrinkage; depending on the level of shrinkage you can have bullets that are either too small, or too large. Too small is less of an issue, but too large can result in excessive chamber pressures. I have had good luck with Lee Liquid Alox and their lube sizer die. Some people prefer the Lyman lube-sizers, which use heated lube, the end product comes out with what most reloaders, would recognize as cast bullets.
Casting Thermometer
Most casting thermometers resemble those like you would use for determining if you have cooked that roast or turkey enough. Except they are capable of measuring the high temperatures of molten lead. Pure lead melts at about 650 degrees F. Whereas certain alloys have lower and higher melting points. The best casting is accomplished about 20-50 degrees over the melting point.
Sources of Lead
You can buy lead at a number of locations, plumbing shops, custom metal shops, gun shops, places that provide linotype for print shops (though not so often any more).
The other option and how I typically obtain most of my lead is as scrap, as I am not particularly discerning when it comes to my bullet making. For the most part, I make adjustments to the mixture while it is molten to give the characteristics I want.
Ideal locations to look for scrap lead are indoor shooting ranges, outdoor shooting ranges, tire shops, print shops and other bulk users of lead. I get most of my lead from tire shops in the form of wheel weights. I am able to obtain anywhere from 25 lbs, all the way up to several hundred pounds per tire shop. Some shops recycle this material, others will sell it to you, and some will give it to you for free.
After getting a quantity of scrap lead, the next thing to do is break it down, this process melts down the lead, removes the dirt, grime, and tire clips. I typically put my large pot on the stove, throw a load of lead in, put the lid on, and turn the stove on. Within 10 minutes, the bottom layers will start to melt down and fill the bottom with molten lead. You can usually push the top layers down and get it to melt down faster. Eventually you will have a puddle of lead with a bunch of crap floating on the top. Scrape this material off; it usually works best if you use a large slotted spoon (pre-heat the spoon by letting it sit in the lead for a minute, otherwise the lead will clump on it.) Once you get the clips off, you can use a smaller ladle to skim the other debris off the top. Sometimes adding candle wax to this helps it clump up, but beware, the wax will boil and catch on fire. While the wax is burning, you can use it to smoke your moulds, which will prevent the lead from sticking to the moulds. Scrape the material off and throw it in a five pound coffee can, some lead will be lost in this, and you can re-melt it later and recover more lead.
Once you decide the lead is clean enough, you can either cast bullets or cast ingots. If you are casting ingots, simply take your large ladle, and fill up each cavity (if your pot is small enough, you can simply lift it up and pour it, but I wouldn't suggest this if it weighs more than 10 lbs).
Wheel weights come in several types, there are tape weights that are normally used on those fancy aluminum rims some people buy, this is usually flat and has a sticky back. Typically these are an alloy that has a higher amount of lead and less antimony/tin than normal wheel weights. I sort these out, and ingot them separately and use them later for customizing my alloys.
Standard wheel weights are long, have a gentle curve to them and come in a variety of lengths and weights. There is a little chunk of steel on these that clips it to the wheel. When you melt the lead, these will float to the surface.
The third type of weight comes in both clip, and in tape weight form. These are made either of steel or zinc, these for the most part do not melt in the lead, however, zinc has a relatively low melting point, and can be melted with the lead, if this happens it can add properties to the lead which make it of very poor quality for casting. You should do your best to remove all of these before you throw the lead in the pot. The easiest way to tell the difference is to hold the weight by the edge, and drag it along the concrete. If it rubs off it is lead, if it scrapes the concrete it's zinc or steel. Separate these, and you can take it down to the metals recycler in your area. (Or you can save it for casting if you alloy brass, bronze or other copper alloys)
The final step is to perform a QC test on your product. Most Hardness testers use a bullet to test. You should now cast a single bullet (see the section below) and put it into the hardness tester. If you find your alloy is soft (it most often will be) you can add tin and antimony to the mix to harden it up. Antimony is a difficult material to come by and has a high melting point, but lead-antimony alloys have a lower melting point than either metal (a property called eutectic), the easiest way is to add linotype or other high-antimony alloy. Tin is commonly available as plumbers solder. Vary these until your bullets are to a level you are satisfied with. For pistol bullets, I am happy with soft lead (just pure scrap), for rifle bullets I would want something harder.
Making Your Own Bullets
Lets assume you have a large pot of molten lead in front of you, a mould, and a ladle. If you haven’t already done so, you should now smoke your moulds either with a carbide lamp, or with a candle. This prevents lead from sticking to the mould. Carbide lamps, and acetylene torches work better than candles. When using a candle don't get any molten wax on the moulds.
Bullet moulds consist of several parts; there are the handles, the mould blocks, and the sprue plate. The sprue plate gives you a little dimple to pour the lead into, and will also cut the sprue off the bullet. Once you are ready to cast, place the tip of the sprue plate into the hot lead. This pre-heats the sprue plate so hot lead doesn't immediately cool and block the rest of the lead from flowing into the mould. When the sprue plate is hot enough, lead will not clump up on it (think of a wick being dipped into hot wax when making candles).
After you have pre-heated your mould, pick up your small ladle and fill up your mould. It takes a little bit of finesse to get this process down, but you will get it rather quickly. Now, you should knock the sprue plate to the side, cutting the sprue (save the sprues and throw them back in the pot next time you need to add more lead). You can now open the moulds and dump out the bullet. I typically use a large metal pail about half full of water to dump the cast bullets into. (Some people prefer dumping them on a damp rag). The bullets are quickly cooled by the water and fall to the bottom. You can now repeat this process until you have the desired number of bullets, or until you run out of lead.
Before you run out of lead, you should sort your bullets, any of them that do not meet your satisfaction can be thrown back in the pot, and re-melted down until they come out as you expected.
The next step in the bullet making process, after you have cast them, is to lubricate them. Lubricating using Lee Liquid Alox is a simple process. Put bullets in a plastic container (I use cottage cheese containers) put some Alox in, and shake. They should come out with a thin coating, if the coating comes out too thick, add more bullets and shake. Once you have applied Alox to them, lay out a sheet of tinfoil outside, and set the bullets tip side up to dry (takes a few hours). Faster drying can be obtained using an electric hair dryer. I also set the bullets tip down in one of the 50 round plastic things that they pack pistol ammo in, then place a piece of cardboard on top, and turn it upside down. This spaces the bullets and makes it easier to lay them out. It is also a good way to count the number you have produced.
After lubing, insert your lubri-sizer die into your reloading press, put the ram into the shell holder slot, put a bullet on top, and run it through the die. Once they come out the other side, they are fit for reloading. I usually put them in a canvas bag (shot bags work well) label them and store them until I'm ready to reload them.
Using a Fire to Melt Lead
While I highly suggest using a modern gas or propane stove, it is possible to use a wood fired stove, or a campfire. Since I typically cast using an old Dutch oven, the process would remain similar, except I would place the oven inside the fire, and I would stoke the fire using an air pump or a fan to reduce the time it takes. The ideal way to do this would be using something similar to the method described in the Gingery books for making your own foundry. Just don't get your cast ware too hot, otherwise you may damage it, a cast iron pot will last forever casting lead, but may only last a few times when casting aluminum or bronze. Temperature is everything. For lead, buy a good casting thermometer. For anything hotter, get a good tool that's designed for it!
Conclusions
Casting your own bullets can be a fairly time consuming process, but it is fun, and informative, not many people out there still make their own bullets, and in a TEOTWAWKI situation, you may be one of the few people with a relatively unlimited supply of projectiles. Obtaining lead from scrap sources is almost free, and lead has an unlimited shelf life. If you combine this practice with other strategic stockpiles (powder, primers) you may have several lifetimes of shooting ahead of you, regardless of external conditions.

JWR Adds : The safety issues of bullet casting cannot be over-emphasized. Needless to say, your lead melting pot should be permanently and prominently marked "Lead Melting Only." This is best done with an engraving pen. Melt and cast only in a well ventilated area. (Lead poisoning is gradual, insidious, and difficult to detect without a clinical lab test!) It is an absolute must to wear long gloves (preferably elbow-length), boots, a heavy canvas or leather apron, sturdy pants and a sturdy shirt with long sleeves, and a full face mask when melting and casting. All it takes is one live primer or cartridge dropped accidentally into a batch of scrap lead, or a bit of water that becomes exploding steam, and SPLAT! Hot lead flies in all directions. So you must wear the proper safety gear from start to finish in the melting and casting process. Also, keep a dry chemical type fire extinguisher and a large bucket of dry sand handy. Do not use water from your quenching bucket to fight a fire started by spilled molten lead. That could cause a steam explosion and, as previously noted, that would send molten lead flying!