With wheel weights becoming increasingly scarce, (entirely due to very careful planning by 'big brother,' meaning it will get worse, and get worse fast!) I decided it is time to write a bit about making up alloy from scrap lead and whatever other kinds of lead are available on the market. The subject and goal of this article then is to give the information needed to make any lead alloy available hard enough to stand the desired pressure and velocity the reader is interested in, or ductility with hardness, which is required for expanding rifle bullets to take big game. (Go to my book for scientific information on making expanding rifle bullets.)
For best control of results one should have an accurate hardness tester. The LBT tester will give you precision hardness measurement, and there isn't another accurate one available, which is easy to read and quick to take hardness measurements in BHN (Brinnell Hardness Number). I will try to tell a few 'shade tree mechanic' methods of gauging hardness if you can't afford a good hardness tester while they are available.
When you have the knowledge of heat treatment first made available in my book Jacketed Performance with Cast Bullets, you will understand that alloy content is a small part of getting lead hard. This book is quite certainly your best source of information on heat treatment. You can read a lot of internet articles about heat treatment, but I've seen too many that are trying to 'reinvent the wheel,' giving information and procedure which aren't good scientific advice. You'll do well to get my book and avoid a lot of wasted efforts because of false notions. However, a tester isn't absolutely mandatory to obtain acceptable results if the content of scrap lead being used is known, because coming close to wheel weight alloy is my main thrust here, and doing so isn't difficult. At least to duplicate closely enough that bullet hardness will be sufficient for most uses, either by water dropping or air cooling.
Hardness Testing Without a Tester
If you don't want to spend the coins for a hardness tester, or just can't afford one, you can get by with a tough dry thumbnail. Make sure you haven't washed your hands for at least two hours, as the moisture will soften your nails for a while. Ditto if you are sweating hard enough to get the fingernails wet. If your thumbnail cuts in fairly easy, hardness is probably under 8 bhn. If, WITH FORCEFUL EFFORT, you can just barely make a little cut into a bullet, hardness is something a little under 20 bhn. If a hard dry thumbnail just skids across and barely puts a shiny line on it, you have something very close to 20 bhn, and possible much higher. This much hardness is adequate for most handgun loads, and can withstand reasonably high rifle velocities. Excess hardness isn't a negative thing in most cases if bullets are properly fitted to begin with, unless one is trying to make expanding bullets, in which case antimony content must be low. Then it becomes more important to measure hardness accurately. Again my book should be your guideline, for both these points.
Testing Consistency and Importance of Lube
When casting with any alloy which is new to you, and of uncertain quality or alloy content, keep your casting technique the same for an entire lot of lead, and don't load up a large lot of bullets until you have shot some, so you know your hardness is adequate. You may not be able to get a dreamed of velocity, but dropping the velocity/pressure a bit will make almost any hardness shoot well with freedom from leading. By the way, right here is a good place to stress the importance of high performance bullet lube. If what you are using gives leading problems, be sure to get some LBT lube, as it will allow higher velocities without leading while maintaining good accuracy, than any other lube I know of. In other words it will allow you to get more performance from an otherwise inadequate alloy than any other lube available. Its storage life is indefinite, well over 30 years without degrading, and no special conditions of storage are required. In other words, high and low temperatures in storage will not effect performance. It will not fall out of lube grooves after long storage, nor melt out except under extremely high storage temperatures.
Necessity of Arsenic
I'll name some of the lead types one can usually find and roughly define what alloy each contains, then explain how to mix them to get good bullet alloy. I'll also talk about alloys available from smelters, NONE OF WHICH CONTAIN ARSENIC BECAUSE OF GOVERNMENT REGULATION. Understanding this capitalized statement is key to making up low cost alloy which will produce good hard bullets, because arsenic is mandatory for a lead alloy to be heat treatable. Just a trace is enough and the most available RICH source is lead shot, new or used. More on this later.
Alloy Significance of Wheel Weight Lead
Wheel weights (WW) have not changed for at least 30 years and contain approximately 1% antimony, a trace of tin, and a trace of arsenic, with the rest lead. Arsenic is the crucial ingredient which makes WW metal capable of high hardness for an antimony anemic alloy. It makes the alloy reach double BHN if quenched from the mold, compared to air cooling, and triple the BHN when oven heat treating. Without arsenic in the alloy, quenching does almost nothing for hardness, which means to obtain a good working hardness, sans arsenic, high quantities of antimony and tin are mandatory. As I go along I'll be advising to add an arsenic source with many of the mixes, and WW is a good source if you can get them at all. Just a small amount is enough to make an alloy heat treatable. As little as 10% WW will make an arsenic free alloy heat treatable, and make pure or dead soft scrap lead capable of attaining a hardness of up to 16 bhn with heat treatment, very adequate hardness for full magnum revolver loads. In other words, if only a small amount of wheel weight metal is available, meter it out to be used as an alloying agent.
Tape-On Wheel Weights
Tape on wheel weights are pure or soft lead. They won't affect the performance of regular wheel weight metal when the quantities normally found in scrap wheel weights are simply melted together. However if you have a large quantity of them, treat them as pure lead.
Acquiring and Using Lead Shot
Lead shot, contains varying amounts of antimony with I believe the average being around 5%, but it is the richest source of arsenic that I know of, at about 1.5% (other than purchasing new metal). Consider the rest of the alloy to be lead. Arsenic is highest in the smaller shot sizes, so if you have to buy new shot to get arsenic, get the smallest size you find on the dealer shelves. (Arsenic is used in shot alloy to make it ball up round when falling from shot towers.) Tin content can be considered 0. Most trap and skeet ranges reclaim lead shot from the ground any more, and some sell it for shooting again. If you locate a source, they will probably have a premium (screened) grade which is more round, and an unscreened grade which will be lower in cost. Possibly even a dirty grade which hasn't had all the rocks and trash removed. Any of them will be affordable if you are only seeking an arsenic source, as very little shot is needed to give the trace of arsenic needed to make an alloy heat treatable. However, if you can get reclaimed shot at a lower price per pound than lead from other sources you can use at least 50% shot safely if you sweeten it up with some tin to slow the arsenic from vaporizing off while molten in the lead pot. I suggest adding at least 2% tin if using high quantities of shot. Keep your pot very well vented to the outside, or do your casting outside with the wind on your back if using a high percentage of shot. Bullets made of only shot, without tin added, will tend to crack after aging, and can break up easily on impact with stout loads, so one is wise not to use lead shot only for casting bullets. Lead shot can be one of the best 'hardening alloys' possible if one adds 4% tin, and not over 5% tin to it, then casts it into small ingots to be used for alloying up any soft lead scrap available. Avoid going over 5% tin because if tin content exceeds that of antimony, rapid age softening will be a problem.
Commercial Cast Bullets
Before purchasing alloy from a smelter and having to pay the high shipping cost, check the commercial cast bullets available on many dealer shelves. Most commercial casters use the equivalent of Number 2 Alloy, which smelters commonly call bullet alloy. This is a good source of tin and antimony and can be diluted with pure or soft lead to roughly equal WW alloy, adding some WW or lead shot to get arsenic. Most of the commercial casters which I've been acquainted with sell their bullets at about the same price per pound as smelters get, and do so because of stiff competition. Their profit is generated by purchasing many tons of metal at a time, at far lower cost than an individual pays for small lots, and shipping to their plant at commercial freight large tonnage rates. If the commercial bullets you look at are fairly shiny you can safely assume they are made of 'bullet alloy.' If you elect to purchase commercial cast bullets for alloy, weigh the different size bullets available and purchase the ones with the lowest price per pound. One pound of commercial bullets to three to four pounds of soft lead, such as range scrap from jacketed bullets, plus an arsenic source, and you'll be in the ballpark with WW alloy.
Linotype and Commercial Lead
If purchasing bullet metal or linotype from a smelter, the above applies of course, as most commercial casters are using new lead from a smelter. However, I've found that linotype and bullet metal are sold at almost the same price, so if that is true of a smelter which you choose to purchase from, get the linotype, because the most expensive parts of an alloy to purchase are the tin and antimony, and linotype has the highest content of both. I have only purchased alloy from a smelter a couple times and when I did, pure lead was quite a bit lower cost than linotype. If you find that true, and don't have a source of scrap soft lead at lower cost, purchase enough pure lead to dilute the rich alloy, be it bullet metal or linotype, down to 1 to 1 1/2% antimony, add a bit of shot or WW and you'll have the least expensive wheel weight equivalent possible for you to purchase as new lead. (Here is a good place to explain the word linotype. It is the casting metal which printers in bygone days used to make a 'line o type.' That's how the name was made, and that's the way it is properly pronounced.)
Bearing babbit is commonly available in scrap metal yards which purchase lead, and the scrap dealers which I've bought from sell all lead at one price. It is a very good deal to purchase it, regardless of what kind it is if you can find it. If a piece of scrap 'lead' looks like part of a bearing, presume it is and hoard it. Babbit is an alloy and also a mixture. Babbit varies widely in alloy content, but is always rich enough in tin to make it flow freely into cold bearing 'boxes,' and high in antimony to make it hard, while the 'mixture' part is copper and other high friction resistant metals, normally ground fine, which are not alloy but are just mixed in, and tend to settle to the bottom or float up, depending on how their specific gravity compares to the alloy part of the mix. These hard bearing particles contribute real quality to cast bullets, because what we are trying to make is a bearing to withstand extreme pressures and friction in the barrel. If you are lucky enough to latch onto a large quantity of Babbitt, you'll find that it makes the highest velocity bullets possible, and some of it will heat treat to extremely high hardness, like 40 bhn. Most readers won't have access to large quantities of babbit but will probably be able to find pieces of it in scrap yards and industrial scrap piles. If you find a babbited bearing in a scrap pile, the babbit inner lining is clearly visible against the cast iron blocks which hold it. Take it home with you. I don't recommend purchasing new babbit because of its high cost, and the fact that it is not true alloy, but contains fine copper and other particles. Use it only if that's all that's available, when purchasing new, or if you get lucky and find it at a scrap yard. It REALLY makes good cast bullets, especially the harder ones. There are a great many babbit alloys, ranging in hardness and wear resistance from not much better than linotype up to very hard. The hardest which I've used was called nickel silver, as I recall, the nickel being in particle form I believe.
Casting With Babbit
Aluminum and copper will not alloy with lead, but will settle to the bottom of a molten pot which is left setting for a while. When casting with an alloy containing babbit, remember to stir it gently, rolling it vertically, every few minutes to keep the mix in an even solution. It will work very well in a bottom pour pot when used this way, if you keep a ladle in the pot and simply roll the melt over every dozen casts or so. Ladle pouring naturally keeps it well mixed without additional effort. One cannot say whether a babbit has arsenic, because there are so many kinds, so it would be wise to presume it doesn't and add some, using shot or WW alloy as a source, when using babbit as an hardening alloy. The arsenic of course being used to gain heat treatability.
Other Sources of Lead
Soft lead is available in many forms. The most common forms which I've found are lead pipe and lead sheet from scrap yards, but one will often find weights which were originally made for machinery counter balancing, some of very large size, like well over 1000 pounds, a gold mine for a bullet caster today. If you get a chance to scrounge through an old scrap yard, with a lot of junk machinery, look closely at the massive metal counter weights used on cranes, forklifts and other equipment. Lead pipe when installed as plumbing was normally soldered together with 50-50 solder, and I've purchased some with such large solder joints that when melted made a very rich tin lead alloy. I've only been able to find tin rich lead pipe like that one time, but most of it will have smaller solder joints. (The joints will be built up, not just a sweated joint as you'll find on copper pipe, so the solder/weld joints are easily spotted.) Dentist lead foil which is used for x-raying, has been reported in literature as pure lead, but one customer who has an abundant supply says it casts like 20-1 tin lead. I can't testify as to what its content is, but would recommend that for most people, who don't have a large quantity available, that it just be alloyed as if it were pure lead. In scrap yards you'll often find an abundance of junk fishing sinkers, especially if you live near the ocean, and they can be made of anything. If I were to purchase a quantity of them, I would melt them all together, or melt in as large lots as practical, cast it off in ingots and experiment with the alloy to see what it does.
Lead From Printing
I have often found print pieces in scrap yards, which were cast for the old linotype printing method. Some will actually be type which will probably be linotype but could be monotype if it was made to be reused many times. (Linotype machines re-melted broken down print boards and recast into the characters needed. This was so the type could be set by punching keys like a typewriter keyboard. Linotype was always used on these machines.) You'll also find strips of fairly shiny lead which will break when bent. These strips were type spacers, and normally made of a lower quality linotype than used for type, but excellent as a bullet alloy source. Sometimes you'll find large bars, normally weighing around 15 pounds, which are linotype, which could be new or used. You'll quickly recognize any of these, and all are usable. Take them whenever you can get them as tin and antimony are high in all, though I don't believe any linotype made in the last 40 years contains arsenic, as it was forbidden by the government some time back.
Solder As A Source of Tin...Silver in Lead
Tin sources vary, but the most available are solders. If purchasing tin lead solder and the alloy is listed, you'll probably get the best deal on the tin by purchasing an electric solder which is 60% tin, 40% solder. 50-50 is the most commonly available GOOD source. Hardware stores will often run deals on solder or simply sell wire solder at a low price and not state the tin content. I would avoid it completely as all that I've tried have so little tin that soldering is near impossible with it. In other words, it's a waste of money to purchase as a tin source. The best solder to purchase for bullet alloying, in my opinion, is silver bearing, no-lead plumbing solder. This contains 95%+ tin, some antimony, and normally an unspecified amount of silver. Silver is called 'rich tin' by lead metallurgists. (A point of interest, which may or may not be of help to someone, sometime, is: Every lead mine on earth has silver naturally occurring in it, in varying amounts. Some lead mines contain more silver than good silver ore, but the silver is hard to remove so is often left in the lead when it is sold as commercial soft lead. That is, the scrap soft lead you purchase may have a significant amount of silver, and if so, will cast with more shine than 'pure' lead.)
Working With Antimony
I've never played with straight antimony, but have read quite a bit about using it. It slowly melts into the molten lead it is laying on and does it fastest if the alloy temperature is high, like close to 900 degrees, as I recall. If I had pure antimony, I would start the process by putting in the pot only a very rich tin source like 50-50 solder, or preferably silver bearing, no-lead plumber's solder, and melt the antimony into this. I would weigh out the tin source so tin content was slightly less than the antimony. This would make a perfect alloying mix to add to any soft lead. Maybe it would be even more perfect if about 10% lead shot was included as an arsenic source.
AVOID ZINC LIKE THE PLAGUE! Only a very tiny amount of zinc will ruin lead.
Lead from Rotometals
I didn't realize that antimonial alloys were lower cost than pure lead, when purchasing from Rotometals. Since that is the case then, don't mess with pure lead, when purchasing alloy new, unless you want to dilute back to get softer and more ductile bullets so they will expand on game. Since most of the lead alloy poured in this country is shot through handguns, and expansion isn't wanted, I would recommend purchasing their bullet casting metal, and adding a small amount of shot or wheel weights to get a trace of arsenic so they the alloy will be heat treatable. Then water drop from the mold. I believe Rotometals pure lead is probably high priced due to its purity, whereas commercial soft lead can contain quite a few other things besides just lead, which makes no difference to the bullet caster. If you can find it, this will probably be much lower cost than high purity 'pure lead,'
Plumbers supplies may still have 'plumbers lead,' which is commercial soft lead and used to be available at very low cost. Older plumbing shops often have it laying around as it isn't used much any more, since cast iron plumbing has gone out.
Lead From Stained Glass Art
I've been able to find quite a bit of scrap lead in the form used by cut glass artists. In fact, I was able to purchase something around 50 pounds just a short time ago. It will be a wadded mess with the strands looking something like an H pattern. (Glass is fitted into both the slots, and soldered at the joints.) I knew some people who made this up, and they always used a soft lead, but were not concerned about it being pure. Wheel weights were way too hard. All I've ever used could be classed as pure lead, for bullet making purposes.
Reducing Large Chunks of Lead
To break a huge chunk of lead down, the easiest way I know of is to place it on a large piece of steel plate or fairly thick sheet which will stand the heat, and run a propane weed burner against the lead. I have a couple of these weed burners with advertised heat output of 400,000 btu's. After a few minutes blasting against a large lead casting, the lead will begin to run off like water from the eaves in a rainstorm. You can catch it at the edge of the tipped steel plate.
For making buckshot you have the same concern as for cast bullets in that you want the shot to cast well and don't want it too turn to powder on impact. So stick with what I recommended above.