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Here's a question from a non-loader which will almost certainly be so simple to loaders that they forgot they even know the answer.

I keep seeing the term "hard cast [lead] bullets." As I say, surely everyone here knows exactly what is the significance of that phrase. If I were on a computer forum someone would tell me to go look it up for myself - assuming I hadn't already. (The problem is, everybody I've found talks about it, but nobody defines it. Or more correctly, nobody I've found compares it to something better or worse.)

But a totally uninitiated person wonders, "Are there soft cast bullets?" "Uncast bullets?" "Cold rolled bullets?" "Hot rolled bullets?" Do manufacturers make cartridges with hard cast bullets? Are they new while something else is old? Are hard cast bullets extremely wonderful for some reason? If so, why are there any other kind? If not, why are they made?

Sorry. Curious dummies who will probably never even touch any loading equipment but who keep seeing the phrase around, want to know.

JimL
 

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here is another novice dummy too!!

So as to not appear more stupid, I will wait to see if we get the correct answer. Because I really have not idea what the difference is either.
 

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I believe this refers to the hardness of the lead used to make the bullet. Bullets are predominately made with lead but also tin and antimony to make the lead harder. The mix or alloy used determines the hardness of the lead.
 

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Okay, no one answered so I looked it up and what I get is that it has to do with the amount of other metals alloyed into the lead to harden it. Which makes sense when you realize that lead buildup can be a problem. Here is the article I found:

http://www.lasc.us/FryxellCommentsCBAlloys.htm

Reprinted with permission of Glen E. Fryxell and Sixguns.com



A Few Comments on Cast Bullet Alloys
By: Glen E. Fryxell

Cast bullet hardness, specifically the hardness of the various alloys used to make cast bullets, has raised a lot of questions and confusion lately. A very common misconception is that leading is caused by the bullet being too soft and the lead gets stripped off or abraded away from the bullet's bearing surface as it passes down the bore. This misguided belief leads many new bullet casters to turn to expensive alloys like linotype, and/or elaborate heat treating methods to harden their bullets, thinking that this is the only way to prevent leading.

There are very, very few revolver applications that require a BHN of over 20. In my experience, revolver leading can almost always be traced to some other factor (inadequate lubrication, improper sizing, barrel/frame constriction, etc.). Only very rarely is barrel leading caused by the bullet being too soft. In support of this claim, let me point out that many muzzle loaders prefer bullets cast from 30-to-1 alloy (which is quite soft, BHN of about 9) and these smokepole slugs are routinely driven to 1300-1400 fps. In addition, high-velocity .22 Long Rifle ammo uses an even softer bullet at over 1200 fps (and if a .22 leads, it's a gun problem, not an ammo problem). Elmer Keith's favorite cast bullet alloy was 16-to-1 lead/tin, which has a BHN of only 11. This is the alloy that gave a roaring birth to the .44 Magnum using plain-based cast bullets loaded to 1400+ fps. Properly loaded and lubed, Elmer's alloy will leave a magnum revolver barrel shiny and clean after a long day shooting.

Plainly stated, hard-cast bullets with a BHN well over 20 are simply not necessary for the vast majority of handgun applications. A novice bullet caster can have much of his or her new-found enthusiasm quenched by the clamor, confusion and paranoia surrounding bullet hardness. This is a shame because understanding alloy suitability is not that complicated and bullet casting really is a lot of fun and allows a shooter (novice and master alike) to get so much more out of their hobby.

Just about every conceivable alloy has been used at one time or another to make bullets. The cast bullet alloys most commonly encountered today are linotype (12% antimony, 4% tin, BHN of 22), Lyman #2 alloy (5% antimony, 5% tin, BHN of 15), and wheel weights (the composition varies somewhat, but usually runs 3-4% antimony and about 0.5% tin and a BHN of 10-12). These hardness values are for air-cooled bullets; heat treating or water quenching these alloys will raise these values notably. For an excellent, detailed treatment of the metallurgy of lead-tin-antimony alloys and how their properties can be best exploited by bullet casters, the reader is wholeheartedly referred to the Lyman Cast Bullet Handbook, "Cast Bullets" by the NRA and "The Art of Bullet Casting" by Wolfe Press. My intent here is to provide an easily digested overview so that new casters will have a clean and simple introduction to the subject and start casting good bullets as quickly as possible.

Historically, tin was used to harden bullet alloys because it was widely available, it was easily mixed with molten lead, and it improved the "cast-ability" of the alloy considerably (tin lowers the surface tension of the molten alloy and allows it to fill out the mould more completely). However, in recent years tin has gotten to be rather expensive. In addition, it's really not all that effective at hardening lead alloys. Antimony hardens lead alloys much more effectively than does tin, and is cheaper to boot, so antimony is the primary hardening component used in lead alloys today. In addition, antimony allows the alloy to be hardened via heat treatment, something the chemistry of tin doesn't allow (and arsenic is even better for heat treating than is antimony). Antimony has limited solubility in molten lead, but tin enhances its solubility through the formation of an inter-metallic SnSb compound, which is more soluble.

Thus each component contributes something different to the whole: tin provides cast-ability (2% is really all that's needed) and "mix-ability", antimony provides hardness and the ability to harden through heat treatment, and a small amount (0.05-0.5%) of arsenic (which in and of itself doesn't harden the alloy appreciably) significantly enhances the heat treat-ability of the mix.

There's been a lot of interest in recent years about making cast bullets very hard (BHN of 20 to 35), either through the use of very high antimony content (e.g. 12%), water quenching or heat treating. The only time that such hardness is needed by a revolver shooter is when dealing with very high pressure, high velocity loads (e.g. .454 Casull). If the hardness isn't required, why use linotype at $1 a pound for sixgun fodder when wheel-weights are free, or at most about 15 cents a pound? Remember, the mighty .44 Magnum was born with plain-based cast bullets with a BHN of 11......and Elmer was pleased.

The metallurgical details of what happens to lead-tin-antimony alloys during heat treatment are beyond the scope of this article, but Dennis Marshall has an excellent treatise on this subject in "Cast Bullets" by the NRA. The bottom line is that lead alloys that contain antimony can be hardened considerably (10 or more BHN) by heating them to about 400 degrees F for an hour or two, and then water quenching. Small amounts of arsenic enhance this tendency considerably. Somewhat similar results can be obtained by casting fast and hot and quenching the hot bullets in water (keep the water away from the lead pot and use some sort of splash control!).

It is important to recognize that lead-tin-antimony alloys work soften (as opposed to brass and steel alloys that work harden), so sizing the bullets will soften those areas of the bullet that get worked. If I'm going to shoot heat-treated bullets, then I size them first (but apply no lube), heat treat, then lube in the same sizing die (this time-consuming process is why I shoot so very few heat-treated bullets). If I'm shooting water-quenched bullets, I choose a sizer die that is just large enough that very little sizing occurs and just run the bullets through one time to get lubed (MUCH quicker and easier).

Tin and lead are infinitely soluble in one another and their binary alloys form true solid solutions. This is how chem-geeks and metallurgists say that the tin is evenly mixed throughout and does not separate. Antimony is much less soluble in lead, and lead-antimony alloys generally have some degree of phase segregation (i.e. antimony crystals surrounded by lead alloy). Lead-tin alloys tend to be much more malleable than do lead-antimony alloys, so straight lead-tin alloys are better suited for cast bullets that are intended to expand readily (i.e. hollow points), especially at lower velocities. They mushroom more smoothly and are less prone to fragment. At higher velocities, a small amount of antimony is acceptable, but it should be limited to no more than 3% to minimize brittleness and fragmentation. The harder (and more brittle) antimony alloys are better suited for bullets that are not meant to expand.

Why not just cast all revolver bullets out of linotype (BHN = 22)? The short answer is because barrels aren't perfect. The long answer is because cast bullet obturation is a good thing. Obturation is the plastic deformation of the bullet alloy as a result of the pressure applied to the base by the burning powder. By making the bullet soft enough that it can deform slightly upon firing, it does a better job of sealing the gases off behind it and minimizing blow-by and the leading that results from it.

Usually when obturation is brought up, the topic of conversation is groove diameter. I'd like to suggest that perhaps this is inappropriate. Most barrels made today are cut with a pretty consistent groove diameter; it may be "tight" or it may be "loose" but it will usually be reasonably consistent throughout its length, generally within +/- .0005" (this didn't used to be true). However, the width of the grooves/lands may well vary by several thousandths. The reason for this is during the repetitive operation of cutting the grooves, the placement of the cutter may not be exactly reproducible, or there may be chatter, or localized hard or soft spots so the cutter drags or skips. Yes, modern barrel-makers are very, very good; but minor variations in the cutting operation, or minor defects within the barrel steel can make the grooves/lands vary ever-so-slightly in width. The forward edge of the land is of little consequence because the bullet's forward momentum is continuously forcing it into this edge. Where the variation of groove/land width raises its hoary head is on the trailing edge.

Once the bullet is engraved, if the land/groove width varies, then the seal is broken on the trailing edge. How many times have you seen barrel leading "follow the rifling"? That is a sure sign that the bullet was too hard for the pressures generated by the load. This is why bullets of moderate hardness are desirable, by obturating they can seal this trailing edge. At extremely low pressures (e.g. 600-700 fps) obturation isn't quite as important since at these low pressures blow-by isn't as much of a problem and the lube serves as a floating fluid gasket and seals the gases (thereby limiting blow-by). Unfortunately, at the higher pressures that most sixgunners operate at, the lube gets blown out the muzzle if it doesn't have obturation playing a supporting role.

So, for routine sixgunning applications what do we want from our cast bullet alloy? In the 800-1000 fps range we should probably keep the alloy at a BHN of 12 or below. From 1000-1400 fps, 12 to 16 is a very useful range of hardness. For velocities of 1400 to 1700 fps, this window slides up to 14 to 20. Above 1700, linotype at a BHN of 22 is an excellent choice.

What does this mean in terms of alloys? For general all-round revolver shooting, I find it hard to beat 10 lbs of wheel weight alloy with a couple ounces of added tin. This comes out to roughly 4% antimony, 2% tin (similar to the old electrotype alloy). This makes excellent bullet metal, it casts well and is hard enough for almost all handgun applications (BHN of about 12). If harder bullets are called for, then this alloy can be water quenched from the mould (or heat treated), which raises the hardness considerably, and I commonly do this for my .44 Mag cast bullets. Its not really necessary, but the water quenched bullets are a little bit more accurate and water quenching is so easy to do, so why not? I tend to think of this as approach as "tight-wad's linotype". I haven't actually measured the hardness of this alloy, but I would guess that it's running around a BHN of 18 or so. It's hard enough, put it that way....

That pretty much covers the non-expanding cast bullets. When I'm casting hollow-point bullets intended for full-house magnum loads (1200-1400 fps), then I soften WW alloy a little bit by using 8 lbs WW with 2 lbs pure lead and a couple ounces of tin. By diluting the antimony with a little extra lead, this alloy comes out a little softer (about 3% antimony, 2% tin) and has a BHN of about 11, and similar to the alloy used by Elmer Keith for his cast HP's (less brittle, more malleable, and very shoot-able). An alternate for this alloy is to mix Lyman #2 alloy with an equal part of pure lead.

For lower velocity HP loads (below 1000 fps), I have grown fond of using 25-to-1 alloy (6 lbs pure lead with ½ lb of 50/50 solder). This alloy is soft enough (BHN of about 9) to expand readily at impact velocities down to about 850 fps (depending on the HP design) and is very useful for things like .38 Special and .44 Special loads. It casts beautifully!

I only resort to using linotype for cast bullets that will be shot above 1700 fps. Expensive high antimony or high tin alloys are really not needed for high-quality revolver loads. Medium hardness alloys will do just about everything you need for sixgun shooting. If you decide that you want them to be somewhat harder, then just water quench the bullets as they drop from the mould. Most leading is caused by some form of dimensional mismatch or by inadequate lubrication, not by the bullet being too soft (don't blame the alloy for something it didn't cause). As the old adage goes, "Moderation in all things...."

- Glen E. Fryxell
 

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Robby said:
Gee, I read it, and I think I understand it. But that was a heck of a lot more information than I expected and possibly wanted.

TY for that post.
Yeah I fell asleep twice reading it and drooled on my keyboard.
 

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Discussion Starter #7
grouchy hippo said:
Yeah I fell asleep twice reading it and drooled on my keyboard.
I didn't fall asleep, but my eyes sure glazed over. I'll have to read that several times before I can make any extremely weird comments like, "I think I understand that!" :D ;D :D

JimL
 

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JimL said:
I didn't fall asleep, but my eyes sure glazed over. I'll have to read that several times before I can make any extremely weird comments like, "I think I understand that!" :D ;D :D

JimL
I cannot believe you said I was WEIRD!!! :rolleyes: Or maybe after this last couple weeks you do know me!!! :D
 

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Adding tin or antimony to lead increases its Rockwell hardness as measured by a hardness tester. Also, annealing it (dropping in cold water after casting) will increase surface hardness. Pure un-annealed lead is "soft". Soft is good for hollow base wadcutters, swells in the bore as with a minie ball in black powder and engages the rifling so as to increase accuracy. HOWEVER, hard cast bullets resist leading of the bore at high velocities.
 

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Discussion Starter #10
NativeTexan said:
hard cast bullets resist leading of the bore at high velocities.
What kind of velocities does it take to start problem leading? May I assume .45 speeds would be pretty much immune? (Not to leading, per se, but to actual problem leading.)

JimL
 

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Robby said:
I cannot believe you said I was WEIRD!!! :rolleyes: Or maybe after this last couple weeks you do know me!!! :D
How dare you misquote me! I did NOT say you were weird. I said extremely weird!! :D ;D :p :fart: :judge: :soapbox: :shooter: :devil: :drool: :bang: :puke: :guns: :rolleyes: :eek: :thumb:


JimL
 

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.45 ACP is not a round I worry about where leading is concerned. Even its fastest 185 grain +P loads can be dealt with using hard cast bullets and any load in the 200-230 grain realm can be soft cast no problem. In .357 magnum, I cast a 158 grain annealed lead with a dash of tin (from solder) and use a gas check bullet design. Addition of gas checks, I can push bullets to over 2000 fps in rifles. I shoot that .357 bullet to nearly 1900 fps out of my Rossi M92 Carbine with no problems at all.

I generally anneal ALL bullets regardless. It solves the problem of bullet deformation when it drops from the mold. I use aluminum molds and can dip the edge of it in the water if I need to cool it off a bit, too. Do that with a cast iron mold and you can crack it.
 

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Discussion Starter #13
NativeTexan said:
.45 ACP is not a round I worry about where leading is concerned. Even its fastest 185 grain +P loads can be dealt with using hard cast bullets and any load in the 200-230 grain realm can be soft cast no problem. In .357 magnum, I cast a 158 grain annealed lead with a dash of tin (from solder) and use a gas check bullet design.
Thanks.

The latter brings up a subject I'm puzzled about regarding .45 velocities.

I was just checking some of my factory ammo bullets. Right on top of the case mouth I get .450 on a CCI and a Taurus X-bullet and .480 on a Blazer Brass. In the same place I get .400 on a Speer. :???:

Am I getting false readings from them shoving the bullet too far in, or is there that much variation between bullets? It seems to me you could lose a lot of velocity if your bullet was too small. I'm not sure it would do the barrel a lot of good either. :p

And I still haven't gotten a satisfactory reply from one of the very first questions I asked when I got on here, including from a Taurus service guy who couldn't answer me on the phone. One way (out of round chamber) the chamber of my .45 is .0012 bigger than some of the cartridges I have used. It occurs to me to wonder if the actual barrel is tight enough to seal in the gas. Especially if some of the bullets are under sized. :eek:

The guy I spoke to at Taurus said he would put a note on the gun, which was in their hands by then. I'll see if the chamber is still that much over sized and out of round when it comes back. One thing is, I don't know how big a proper chamber should be in the real world.

Small bullets - big barrels? Hmmm... Is that why I don't get as much recoil as I expected from a .45? :???: :???: :???: :???: :???:

JimL
 

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I don't quite understand what and where you are measuring, guessing it's bullet diameter, but it's hard to understand the way you word it.

Slug the barrel. Run a sized soft lead bullet down through it and measure. Bullets, all of 'em, should measure .451" or perhaps .452 for a cast one. You really cannot get a good measure on it in the case. as you have to measure down off the ogive near the base. However, .480 inches would be dangerous and wouldn't load in a .45 caliber gun, so I'm thinking there's a glitch with the calipers on that one. No way you're going to force a .480 bullet down a .451" bore.
 

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JimL said:
Thanks.

The latter brings up a subject I'm puzzled about regarding .45 velocities.


I was just checking some of my factory ammo bullets. Right on top of the case mouth I get .450 on a CCI and a Taurus X-bullet and .480 on a Blazer Brass. In the same place I get .400 on a Speer. :???:

Am I getting false readings from them shoving the bullet too far in, or is there that much variation between bullets? It seems to me you could lose a lot of velocity if your bullet was too small. I'm not sure it would do the barrel a lot of good either. :p

And I still haven't gotten a satisfactory reply from one of the very first questions I asked when I got on here, including from a Taurus service guy who couldn't answer me on the phone. One way (out of round chamber) the chamber of my .45 is .0012 bigger than some of the cartridges I have used. It occurs to me to wonder if the actual barrel is tight enough to seal in the gas. Especially if some of the bullets are under sized. :eek:

The guy I spoke to at Taurus said he would put a note on the gun, which was in their hands by then. I'll see if the chamber is still that much over sized and out of round when it comes back. One thing is, I don't know how big a proper chamber should be in the real world.

Small bullets - big barrels? Hmmm... Is that why I don't get as much recoil as I expected from a .45? :???: :???: :???: :???: :???:

JimL
Sounds like 3 different caliber bullets.
 

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Discussion Starter #16
NativeTexan said:
I don't quite understand what and where you are measuring, guessing it's bullet diameter, but it's hard to understand the way you word it.
I don't know how else to put it. I was checking factory ammo bullets right against the case mouth.

You really cannot get a good measure on it in the case. as you have to measure down off the ogive near the base.
OK, got that. They stuff the full sized part of a bullet down inside the case.

However, .480 inches would be dangerous and wouldn't load in a .45 caliber gun, so I'm thinking there's a glitch with the calipers on that one. No way you're going to force a .480 bullet down a .451" bore.
You got my comment about the over sized chamber and maybe a big barrel, right?

Well, I dunno. Looks like I may, indeed, have to slug the barrel if they don't give me a new one. (Probably will anyway if I can find a bullet somewhere.) I have a Taurus x-bullet here that I shot into water. It is out of round too and measures a maximum of .500 at the major diameter, .450 at the minor diameter.

If the barrels are supposed to be .450 in the grooves, this one was apparently intended for Taurus's new competition to the Desert Eagle! ;D :D :yipee:

Oh, the .480? Only .455 at the smaller dimension.

JimL
 

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Is accuracy bad on the gun? If it shoots straight, I doubt anything is out of whack. The one oversize chamber I'd wonder about. You could do some accuracy comparisons between cylinders, number the cylinders and shoot same cylinder against itself and each other to determine if the oversize chamber is affecting accuracy. If not, I wouldn't loose sleep over it. When the cartridge fires, the case will swell out into the chamber. No pressure will be lost.

I don't have a revolver with an oversize chamber in the cylinder. I do have revolvers that are slightly larger than others. My 4" 66 is larger in the chambers by a couple of thousandths than my M85 or my Ruger SP101, yet it is superbly accurate. I load wadcutters sized to .357 that sometimes won't go in the 85, but drop right in the 66 and shoot into 1" at 25 yards. In that gun's case, larger chambers is a good thing, LOL!
 
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