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View Full Version : Lead Hardness Tester (Versifier)



Kirbydoc
08-30-2014, 03:50 AM
Oh Versifier...
I just came across (medical) Antimonial lead which I am thinking of testing to determine hardness. I heard that someone said that Versifier said that Lead hardness testers were unnecessary. Would you enlighten me please?
http://wildlife.ohiodnr.gov/portals/wildlife/Species%20and%20Habitats/Species%20Guide%20Index/Images/Thumbnails/barnowlTN.jpg

fryboy
08-30-2014, 12:03 PM
useful yes , needed ? no sir ,one has to but stop and consider that for the longest time they weren't commonly available and people did just fine , here's a ummm work around lolz
http://castboolits.gunloads.com/showthread.php?75455-Testing-hardness-with-pencils

as for your medical lead ... there's several variations , most were used for storage/transport of various nuclear medicine and fall under the general description of "isotope lead containers" , here's the best link i can offer on isotope containers ,of note they are broken down by descriptions at the top of the tabs ,most are alloyed some are pure [shrugz]
http://fellingfamily.net/isolead/

versifier
08-30-2014, 03:50 PM
With a little experience that you can gain in a few hours, a powerful magnifier, and some common sense, you don't need a fancy tester.

Here's how you test relative hardness: You need two ingots of known hardness, one pure lead for softest, one linotype for hardest, one test ingot of unknown hardness, a 1/4" ball bearing, and a bench vise. Put the ball bearing between either control ingot and the test ingot and clamp them in the vice until the ball bearing begins to impress into both. Repeat test with the other control ingot and the test ingot using the same amount of force to close the vise. This is the part where accuracy can suffer - unless you can control and repeat the amount of force applied to the vise every time. I use 20# of barbell weights on the end of vise screw's sliding handle (and shims when necessary so it is in the same part of its arc each time regardless of the ingots' thicknesses). YMMV. Compare the relative sizes of the impressions between the known hardnesses of the control ingots and those of the test ingot under magnification (there are inexpensive pocket scopes and hand magnifiers that have a sizing grid etched into them so you can actually measure them accurately). Most sizing kits you buy use the same methods with their own little expensive tools of varying quality of crudeness, but this one works with the tools at hand in most shops and requires only common sense. When you have used the test several times, you can then more easily estimate an unknown alloy's hardness by simply pressing the tip of a razor knife into it and a known alloy side by side and judging for yourself by their relative resistance to the penetration of the blade.

Antimony is good. It means that you can make harder bullets in two ways. The first is the easiest and most stable over time, simple alloying, with the hardness varying with the percentage of antimony. There is for instance, some antimony and some tin in what we call "wheel weight alloy". In point of fact no two batches of smelted WW's are the same hardness as the proportions of the three metals vary considerably from batch to batch. But throughout its range of variation, it casts a bullet that is harder than pure lead but still soft enough to expand in living tissue. To make a consistent, repeatable alloy that anyone could rely on and get somewhere near the drop weights they publish with their moulds, Lyman came up with its #2 alloy. It is a tad harder than most commercial WW mixes, but it still expands well and due to its slight hardness advantage it can be shot at higher MV without leading the barrel. Linotype, which contains the most antimony and is the hardest of the shootable alloys, does not expand at all, like a FMJ bullet, and it is so hard that if it hits something solid, like a major bone, it shatters into small fragments instead of penetrating into the vitals. Lino makes excellent long range target bullets. Cutting lino with pure lead in varying amounts allows you to customize an alloy repeatably. Antimony in the alloy also allows you to heat treat your bullets for maximum hardness, a technique only effective if used after resizing as lead alloys soften when worked. Heat treatment only lasts a year or so, the altered hardness slowly returning to its original as-cast state. It doesn't work with conventional lube/sizer setups as the lubes will not stay on the bullets for heat treatment but must be on them for resizing. Tumble lubing and push through sizing works as LLA will stay on without deteriorating far above the 4-500*F heat treatment range, and it can be reapplied. But that is a whole different topic.

I couldn't tell you exactly how hard any of my usual working alloys are. But I keep huge supplies of pure lead and wheel weight ingots and a smaller stash of linotype ingots and I can make the alloy I want within the desired hardness range. The pure lead and the lino I can look up if I want numbers. My handgun alloy, used for .38/9mm/45 bullets, is as soft as I can get away with and I can make it by diluting either WW's or lino with pure. How hard is it exactly? Way much softer than any commercial "hard cast" bullet. (In fact, when I get them donated to the cause I usually melt them down and dilute them with two or three times their weight in pure lead and cast them in the correct size). As long as whatever the WW's come out of the smelter at expands properly at hunting velocities (1700-2500fps) and isn't so soft it leads up the barrels I'm happy in my hardness number ignorance. I know by relative tests exactly how hard this batch is, but I know it by the feel of the relative hardness under my hand tools. I'm not trying to make this sound like some arcane alchemy requiring years of experience, it isn't. With a bit of patience and ready access to aloe vera for burns you can get the hang of it in an afternoon or two. Do wear eye protection at all times.

Damn it Kirbydoc, you made me write an article. This is all your fault. (Various unprintable mumbles and mutterings in the background you cannot hear online.) You really have to work on your sense of timing. Now I'll have to sit down and rewrite it all and finish the damned thing when I was right in the middle of research and background for a fiction project. I needed a break from that anyway I guess. Thanks!

Kirbydoc
08-31-2014, 03:55 AM
Thank you fryboy and Versifier! Greatly appreciate the responses.
So sorry Versifier...(Hee, Hee Hee) no really, my evil twin wrote the hee hee's.
I don't have any pure lead except sinkers but maybe I can make them do.
Linotype is another issue. Have to buy it I guess.

versifier
08-31-2014, 07:15 PM
Seven pages. Probably will end up around five. I'll post it when it's done. Now I'm thinking of another very technical one specifically on cast rifle hunting bullets.

Kirbydoc, if you know a renovator/contractor (old lead plumbing), a roofer or a mason (old and scrap pieces of lead flashing), it's pretty easy to come up with pure lead scrap if they know you're looking for it. Medical lead I have encountered has mostly been very close to pure. Birdz used to use pure lead foil from old dental x-rays (it was good stuff but fairly labor intensive) until I got us several tons of old lead pipe.

versifier
09-01-2014, 07:09 PM
Alright. I have both of them finished. I am waiting to hear from GLMaster about publishing them on the GL Home Page. If he goes for them I'll post a link, if not I'll post the text here.

versifier
09-08-2014, 07:12 PM
Haven't heard back from Willy yet, so here it is as promised:

Myths and Facts of Cast Bullet Hardness
copyright 2014, by Thomas J Diegoli

People can get obsessive sometimes, and we handloaders are certainly not immune. In fact, our obsessiveness and attention to picky details allows us to make safe and accurate ammunition. One of the more amusing handloading trends in recent years has to do the myths and realities of bullet hardness and how it actually applies to real world shooting.

For someone considering shooting cast bullets or taking the larger step of casting their own, there is a lot of information to be found, a daunting amount, and much of it targeted at consumers to sell them inferior products. A fair amount of what’s out there about handgun bullets is reasonably accurate, but much of it, especially with regard to bullet hardness, is merely mindless repetition of untested myth or outright fiction with absolutely no real world experimentation to back it up. Forget about cast rifle bullet information, most of what has been published about them should be labeled as fantasy.

When I make a definitive statement, it is because I have actually tested it and I am speaking from experience. I know little about competitive shooting, or loading shotshells, or building benchrest rifles and I offer no opinions on such topics. I build large game hunting rifles on Mauser and Savage actions and I load specialty ammo for them with cast and jacketed bullets. I have been casting handgun and rifle bullets for almost forty years.

There are three major factors that determine accuracy and performance of cast bullets: dropped or sized diameter, hardness of the alloy, and what is used to lube it. Mostly I will discuss hardness here, but some explanation of the other factors is needed for understanding the whole picture, so bear with me.

Most commercially and home cast bullets are handgun bullets, and the prevailing myth about them is that harder cast bullets are “better” bullets. Better for whom?

A commercial caster wants to sell you a good looking bullet that stands up to handling and doesn’t make a mess. A noble aspiration, but the result is all too often at direct odds with what will shoot best and most accurately in your handguns. The common result of this trend is a bullet of too small diameter, of an alloy that is four or five times harder than necessary, and lubed with a hard plasticy lube chosen only because it doesn’t melt or fall out of the lube grooves before the box is opened. A product that looks and handles like jacketed bullets when you load them. But they are not and they don’t shoot like jacketed, even when they do use the same loading data as jacketed handgun bullets. The rules of cast are different and they aren’t written down.

So what are the “cast rules”? Here are the basics:

Size. A cast bullet needs to be somewhere between .001-.003” larger than the barrel’s measured groove diameter. “Measured” means slugged and mic’d, with an actual lead slug driven through the bore and measured with a real micrometer, not approximated with the inside points of a caliper, even a fancy digital. An undersized bullet (the same or smaller diameter as a jacketed bullet) will be less likely to obturate well to the barrel’s grooves, more likely to have combustion gas work its way around it when it is moving down the barrel (termed “gas cutting”), and more likely to tumble as it leaves the barrel due to changes in the bullet’s base as a result. Undersized bullets have a much greater propensity to leave lead fouling in the barrel, too.

Lube. Lube isn’t as critical with low velocity handgun rounds as it is with higher pressure and velocity applications, but softer lubes are in general more usable over a much wider range of velocities and will usually produce better accuracy. Hard lubes are mostly useless with velocities over 1000fps and totally useless above 1500fps.

Hardness. Hardness is a two way street, and it needs to be balanced against the bullet’s velocity and purpose. Pure lead is the softest, expands best, and obturates to the grooves of a barrel best. What pure lead lacks is strength, the downside being barrel leading and then stripping if pushed with greater rotational energy than it can handle. So we add antimony and/or tin to increase the alloy’s strength and with it the hardness also increases. Too hard, no expansion. No big deal for target bullets, but useless for self defense or hunting bullets. Too hard, the bullet will shatter if it hits anything solid like a heavy bone and leave a wounded animal to die a lingering death. The harder the bullet, the greater the chamber pressure needed to make it fully obturate without fouling or cutting. (Adding an undersized bullet to the equation can make for horrible lead fouling in the barrel’s grooves.) Size over groove diameter is more important than hardness, but awareness of both is necessary. A plain-based handgun bullet should be just hard enough so it doesn’t lead or strip at its planned velocity. Any more hardness than that minimum is a waste of expensive tin and antimony and totally unnecessary.

Yes, gas-checked revolver bullets, like rifle hunting bullets, should be proportionally harder to handle higher velocities and greater corresponding rotational energies, but they still need to be soft enough to expand properly, and their size is still a greater factor in accuracy than their hardness.

Buying casting metals can get expensive, and most of us get by scrounging up whatever we come upon, casting it up, and shooting it. That said, all we really need is a way to figure out approximately how hard our unknown alloy is and how it then add what, if anything, is needed to make the alloy that’s needed for the specific kind of bullet you want to cast.

We are looking for practical repeatable results that you don’t need a math degree to arrive at. It would be nice to put an actual numerical value on your alloy’s hardness, if only to be able to clearly communicate to others how to recreate your alloy. Nice, but not essential to the home caster, and of dubious practical value in turning out usable shootable bullets for target and hunting.

So, how does this work in the real world?

Let’s say you have a yard sale find that looks like it might be castable. The obvious question: Where on the hardness scale between pure lead and linotype is the sample and how to figure it out? We are told that a friend’s mystery metal is “(medical) antimonial lead”. In reality, it could be almost anything mostly lead that might or might not have a usable amount of antimony in it, but as long as there’s no zinc in it, it can be used either as is or alloyed to make something shootable to someone.

Since we need it in a usable form to test it, the first thing is to smelt some and cast it into a few of the same handy size 1# ingots you use for all your casting alloys. Let it cool completely, then label the unknown ingots clearly so they don’t get confused with your known control samples.

Here's how to test relative hardness: You need two control ingots of known hardness, one pure lead for softest, one linotype for hardest, one test ingot of unknown hardness, a ¼” ball bearing, and a bench vise. Put the ball bearing between either control ingot and the test ingot and clamp them in the vice until the ball bearing begins to impress into both. Repeat test with the other control ingot and the test ingot using the same amount of force to close the vise. The harder alloy will have a smaller diameter impression with the same force applied in the same test than the softer one. This is the part where accuracy can suffer - unless you can control and repeat the amount of force applied to the vise every time. I use 20# or more of barbell weights on the end of vise screw's sliding handle (and shims when necessary so it is in the same part of its arc each time regardless of the ingots' thicknesses). YMMV.

versifier
09-08-2014, 07:13 PM
Part Two:

Compare the relative sizes of the impressions between the known hardnesses of the control ingots and those of the test ingot under magnification (there are inexpensive pocket scopes and hand magnifiers that have a sizing grid etched into them so you can actually measure them very accurately). That’s all there is to it.

Most hardness testing kits you buy use the exact same methods with their own little expensive mechanical and optical tools of varying qualities of crudeness or exactitude, and all will give you workable numbers, but my way works with the tools at hand in most shops and requires only common sense and some practice. When you have used any ball bearing penetrative test several times, you can then take the next step and learn to easily estimate an unknown alloy's hardness by simply pressing the tip of an awl or a razor knife into it and a known alloy side by side and judging for yourself by their relative resistance to the penetration of the tool. And after that the expensive tool gathers dust on the shelf.

But the mystery metal is supposed to be something called “antimonial lead”. What is antimony and why should it be in my casting alloy? Antimony is a highly toxic metal in its free (non-alloyed) state, but it can do good things and be safely handled in a lead alloy. I don’t know how much antimony is in the mystery metal without some kind of comparison to tell me how hard it is. Antimony in the alloy means that you can make much harder and stronger bullets than you can with pure lead. You can do that in two ways, by alloying and by heat treating.

The first is the easiest and most stable over time, simple alloying, with the hardness varying with the percentage of antimony. There is for instance, some antimony and also some tin in what we call "wheel weight alloy". In point of fact no two batches of smelted WW's are the same hardness as the proportions of the three metals vary considerably from batch to batch. But throughout its range of variation, what we loosely refer to as wheel weights will cast a bullet that is harder than pure lead but still soft enough to expand in living tissue. “WW alloy” as a term is not too specific as to exact composition, but rather descriptive of its general utilitary properties over a range of its proportional components. Tin hardens the alloy to some extent also, and it increases castability by improving fillout of the individual mould cavities, fewer rejects. It is common practice to add tin to a melt in the form of plumbers’ solder in roll or bar form, or old pewter.

Skipping a lot of history, when they wanted a consistent, repeatable alloy that anyone could rely on to get somewhere near the drop weights they publish with their moulds, Lyman came up with its #2 alloy. It is a tad harder than most commercial WW mixes, but it still expands well and due to its slight hardness advantage it can be shot at higher MV without leading the barrel. Lyman #2 is also commonly used as is for some target and handgun bullets, and while satisfactory is really not optimum for either.

Linotype, which contains the most antimony and is the hardest of the shootable casting alloys, does not expand at all, like a FMJ bullet, but it is so hard that it is brittle and can shatter. If it hits something solid, like a major bone, it shatters into small fragments instead of penetrating into the vitals. Lino makes excellent long range target bullets. Cutting lino with pure lead in varying amounts allows you to customize an alloy repeatably.

Antimony in the alloy also allows you to heat treat your bullets for maximum hardness, a technique only effective if used after resizing as lead alloys soften when worked. It is after all the driving bands of the bullet that we want at their maximum possible hardness, sizing them post heat treatment negates that, leaving you with a hardened nose and softer as-cast driving bands. Heat treatment only lasts a year or so, the altered hardness slowly returning to its original as-cast state. It doesn't work with conventional lube/sizer setups as the lubes will not stay on the bullets for heat treatment but must be on them for distortion free sizing. Tumble lubing and push through sizing works as LLA will stay on without deteriorating far above the 4-500*F heat treatment range, and it can be reapplied.

I don’t usually work with harder target alloys, but I am well aware of their properties because I have tested just about every castable alloy I’ve gotten my hands on or made up to order over the years. In point of fact I never ever use anything like pure lino or hardened lino for hunting bullets, the primary focus of my personal interest in cast rifle bullets. Lyman #2 (or its close equivalent) is the hardest alloy I use for them. I couldn't tell you exactly how hard any of my usual working alloys are on the Brinnell scale, or the exact percentages of their component metals. I keep huge supplies of pure lead and wheel weight ingots and a smaller stash of linotype ingots and I can make the alloy I want within the desired hardness range. The pure lead and the lino I can look up if I want their actual numbers.

My handgun alloy, used for .38/9mm/45 bullets 1000mv or less, is as soft as I can get away with and I can make it by diluting either WW's or lino with pure lead in a 1:4 or 1:5 ratio, or just by adding 3-4% tin to pure lead. How hard is it exactly? Way much softer than any commercial "hard cast" bullet. (In fact, when I get them donated to the cause I usually melt them down and dilute them with four or five times their weight in pure lead and cast bullets with the resulting alloy in the correct size). I want something soft enough to obturate well at low pressures and just hard enough so there is no lead fouling and no stripping. I wouldn’t consider it hard enough for a big revolver bullet that would call for a gas check.

For my rifle alloy, as long as the current batch of WW's coming out of the smelter at expands properly at hunting velocities (1700-2500fps) and isn't so soft it leads up the barrels at the upper limits I'm happy in my hardness number ignorance. I know by relative tests just how hard this current batch is, but I know that by the feel of it under my hand tools.

I know enough to know that if my .310” 175gr #311041 FNGC bullet, shot within 200yds, is properly placed in the boiler room of a large deer it will expand at least 20%, expend the majority of its kinetic energy in its quarry, kill it quickly and cleanly. If I hit the 100yd steel gong with it I will find a flattened lead alloy slug with gas check still attached under it retaining at least 60% of its cast weight.

For comparison, a linotype .310” #311291 RNGC target bullet of approximately the same weight fired on the same steel gong would shatter completely, I might find the copper gas check stuck to the metal of the gong or in the grass in front of it, but other than that it will have disintegrated completely. I might be able to push this bullet way above 2600fps and still get decent accuracy without any leading in the grooves for long range paper targets, but it would be unethical to ever fire one at a live target.

I don’t need exact numbers to come up with workable alloys for what I need to shoot, I just need a practical way to judge the relative hardness. My performance requirements can be met by a reasonably wide range of possible alloys of the three component metals. If it were a business and I had to turn out a consistent high volume product, then I would need exact ratios and casting machines and hardness testers and more blood pressure meds and thank you but no, not for me.

I'm not trying to make this sound like some arcane alchemy requiring years of experience, it isn't. Anyone can figure out what the properties of the mystery metal might be with a little effort.

Be smart and do wear eye protection at all times when smelting and casting, and only cotton or leather, never synthetics which melt and stick to your skin when hot metal hits them. Long pants and solid topped footwear help too. Lead alloys don’t stick to dry skin, but they will burn it. Wash your hands thoroughly every time you pause and before you touch anything else, especially food or drink. Poisonous lead oxides are all highly soluble in water. With a bit of patience and ready access to fresh aloe vera cuttings for burns you can get the hang of estimating your alloy’s hardness in an afternoon. With some practice and some common sense, you really don't need to buy a fancy tester.

Once you know what your alloy should be, you can achieve it quickly. There’s a lot of elbow room in both handgun and rifle hunting bullet alloys and as long as I know the alloy will do the job I don’t need to overthink it or put a number on it. That leaves me free to concentrate on casting, loading, and shooting techniques.

Kirbydoc
09-08-2014, 07:44 PM
Versifier, thank you so much for sharing. I may need to vary the method some but this will be a great help. Now to find some linotype.

Mike in tx
09-08-2014, 07:48 PM
Thanks V. I think to much about "hardness" but am changing d/t you.