Lead Casting Part 2

By soundguy, May 2, 2017 | |
  1. soundguy
    In part 1 of my article I covered finding and preparing your lead for use. I’ll recap the safety warnings from Part 1:

    For anyone thinking they might want to get into casting, I recommend doing the same. Research, Research, Research, online and in books, thru contacts at clubs or being mentored by an experienced person locally. As with reloading, there are a few different paths you can take, and thus different equipment and styles. Above all, remember safety. Lead melts at about 622’F, Tin melts at 450’F, and raw antimony melts at 1167’F. These are the main alloy metals you will be using. There are others, but that’s left to the more advanced caster. Since you will be working with molten metal of this temperature, personal safety practices and protective gear will be needed. Also, keep in mind that you are working with toxic heavy metals. Don’t eat, smoke, drink, etc, while working with your lead. The white powdery oxide is also dangerous on lead. Wash any exposed skin thoroughly after exposure. Avoid breathing the fumes that smelting and lead casting produces, including the fumes from burning flux materials. Always cast in an area with plenty of open air ventilation, and not in confined spaces. Be very careful about getting water or other liquids into your lead pot. Water droplets can fall into your pot and turn into a small steam explosion instantly, tossing hot lead streamers everywhere. This is why protective gear like gloves, aprons, and appropriate eye protection is needed, perhaps even breathing protection depending on the amount of fumes your pot gives off. These warnings are not meant to be exhaustive, but rather serve as additional information that you can use along with other safety information you will find in reference materials, such as the Lyman cast bullet handbook. For those looking for research material, I highly recommend the following: Lyman cast bullet handbook, ( available in print ), and as an online resource, use your browser to search for “ From Ingot to target: A cast bullet guide for hand gunners. Also, the ‘ Cast Bullets’ publication from the NRA is a useful tool. Many other reference books and articles I have read refer back to these 3 works.

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    Ok, now that you have been warned, again, about working with hot metal, hot tools, etc, and have been given a few paths to explore to find other casting reference material, lets get to it.

    Making bullets!

    First thing you need to do is get a bullet mold! Lots of choices out there from pretty cheap to pretty expensive. RCBS, Lyman, Lee, NOE, etc. Molds will be different materials, but typically, brass, iron, iron alloy, and aluminum. Many molds will want to be candles or smoked prior to use. You should also inspect your molds , clean them and remove any flashing that remains from the milling process. Molds come in many different cavity quantity options. 1, 2, and 6 cavity molds are the most common. 6 cavity molds are great for making a ton of bullets, but are harder to learn on. I recommend starting with a 2 cavity mold if possible, then work your way up. Lee makes inexpensive molds, generally about 25$ with handles.

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    Preheat: you will want to preheat your molds prior to each use. An old garage sale hot plate will work, or you can rest your mold on your casting pot during warm up, or even dip the corner of your mold into the melt for a few seconds before using. Aluminum molds heat fast and cool pretty fast.. iron and brass molds heat slower and cool slower. You will eventually find a good time rhythm with pouring, dropping, and re pouring to keep your molds temperature correct.

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    You may have to adjust your pots temperature often, especially when adding more ingots. I recommend getting a thermometer for your pot. Plenty of people make them, I use an RCBS. It lets you come up to a repeatable temperature that you know works for your mold and alloy, and takes most of the guess work out. Tip: if your bullets are not filling out on your first few casts, don’t panic, let your molds come up to temp, and then keep trying, if still not filling out or looking wrinkly, try adding more tin, tin makes pretty bullets with reduced wrinkle possibility and sharp corners. Also, if your bullets come out looking frosted, your mold is too hot. ( most of them frosted bullets shoot just fine, so you don’t have to toss them back in if you don’t want to. I frosted my first run of 38spl bullets when I started, I kept them and fired them, worked great, quickly learned to make good bullets after that ).

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    Once you have your molds, then you need a melting pot. Lots of options here, with the average being 10-20 pounds for hobby use. ( yes there are pots as low as 4 pounds, and advanced hobby and commercial pots up as high as you want ). There are a few pot types that can be broken down into bottom pour, open top and dipper, and direct top pour. For example, a 10 pound bottom pour pot costs about $55.00

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    Bottom pour. It is an open top pot, and a spout either on the bottom or low on a side. You add your lead to the pot, melt, flux it, and then when you actuate the pour valve, the lead pours from the bottom. I like this version the best. You can leave your dross on the top without constantly skimming it and it forms a protective oxide layer. Hold your mold under the nozzle, fill, overfill a touch, then wait for the mold’s contents to harden and knock the sprue cutter open on top and drop your bullets. I like dropping my bullets into a water bucket with a old beach towel on top of it with a hole in it. The bullets drop into the hole along with the excess sprue pieces, and the towel catches the splashes. You can also drop into a bucket lined with old blue jean material to soften the landing. Excess sprue material can be collected periodically and added to the pot. I don’t let my bullet layers get too deep in a dry catch bin, I like something soft for them to land on while still hot to prevent denting. Water dropping on the other hand, is not a problem. They cure fast when hitting the water.

    Open top with dipper. This is literally a large open top pot, and you use a ladle dipper to dip in, and then pour from the ladle to the mold. I don’t prefer this method, though it was the very first I tried. With this method, you need to keep the dross cleaned off the top of the lead to prevent getting it into your ladle. Ladles can be had in the 8-40$ range. The open top pots are generally larger to allow dipper use, and thus cost more. ( The Lyman Lead Bullet Casting Book shows you what a lead dipper pouring into a mold looks like on it’s cover. )

    For reduced needs production, you can get a small pot that has an insulated handle and you heat in the pot, and directly tip the pot to pour into your molds. These need to have their dross scraped often as well.

    Now you have your bullets, now what?

    You may or may not need to size your bullets, and you WILL have to lubricate them. A cast bullet typically will need to have a diameter of .001 to .002 larger than a jacketed bullet in the same application. For example, the jacketed projectile for a 45 ACP would be .451, I like to run .452 in a cast projectile.

    Some molds tend to drop a good diameter and can be used without sizing. It very much depends on the mold, the alloy you use ( varying shrinkage characteristics ), and the target diameter you are looking for. Mold construction will provide grease grooves on the bullet for lubrication. Some molds make a microgroove, typically having an entire shank of the bullet, before the ogive, as micro grooves. Standard grease grooves are larger, and depending on bullet size, there may only be one, but could be more. These grooves are larger. The micro grooves molds can use a thinner lube product called ALOX, while the traditional larger grease groove bullets are usually lubed with a hard waxy lube. ( exceptions exist to both statements! ) My cat sometimes supervises the Alox lubed bullets as they dry.

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    Once you find out what size your bullets drop at, then you can decide if you need to size them. Sizing is typically done thru a inexpensive press mounted simple push thru sizing die ( 25$ from lee, single caliber set, includes a small bottle of lubricant ) , or thru a more complex press/die system that has change out caliber inserts, possibility of a lubricant heater, a cavity to hold a hard stick style lube. There lubrasizers are generally much more expensive, but some people swear by them. I use the economical push thru die sets. You can make or buy your own bullet lube. Making bullet lube could also be it’s own article, so for now, I suggest you buy a commercial bullet lube and lubrication method. Alox can be tumble applied. Add bullets to a small container, squirt in alox, tumble them around to coat, then dump them out on wax paper to dry. Then size them, then relube them. They are then ready to go. Pan lubing is also possible. Set your bullets in a shallow pan, melt your hard lube and pour over the bullets, when the lube cake hardens, use a dowel rod to push the bullets thru, then size them. As you get more experience you can experiment with lube recipes for online.

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    Lastly, as you may have surmised, casting will produce good useable bullets at a fraction of the cost of jacketed projectiles. However, these cast bullets typically load with different data that is reduced in pressure and feet per second. Occasionally you will have an application where you want a cast bullet, but want to push it faster than you normally would want to. Or you may have a situation where there is gas cutting of your lead bullet and melting the base of your projectile and leading your barrel. While generally going to a slightly harder alloy can help, there are times when too hard an alloy can be detrimental. One thing you can do is to get a mold that is made to leave a gas check shank on your bullet. A gas check is essentially a small cap that is crimped onto the base of the bullet. Usual materials are copper and aluminum, in the .0145 - .016 thickness range. Gas checks can be bought commercially from several sources, and you can even buy a tool to make them yourself, if you desire. Commercial gas checks can run around 35$ per thousand. If you don’t use many, making your own checks may not be a good investment. Gas checks are installed by your sizer die, whether it is the cheap sort of push thru sizer, or the more expensive lube and size die.

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    Once gas checked your bullets will have that small cap on their base and it will resist gas escaping beside the base of the bullet and prevent or reduce cutting and leaving lead fouling in your barrel.

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    Casting is one of those hobbies where each piece of gear, each decision of molds, discussion of hardness, etc, could be it’s own article. I’ve tried to touch on the high points that I discovered during my brief but fun adventure into casting. Be safe and enjoy custom making projectiles to fit your needs.

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