I do not understand why a lead cast bullet can only contain a few percent (2 to 3) parts of tin to be classed as hard. If an alloy of 70% lead and 30% tin was used it will still be “softer” than copper. What gives?
Historically, bullet lead is hardened, principally, by addition of antimony and minute mounts of arsenic. Lead will harden slightly with 2-3% of tin added but more than this will not make much difference, at least not enough difference to justify using expensive tin to do it. Tin is added to lead in small amounts because it will enable better mould fill-out than will pure lead, and not to (appreciably) harden the alloy. More than 2-3% tin is a waste of money. Many old wives tales abound about bullet casting alloys; these can be destructive of bullet caster’s efforts if they are believed.
I have come into possession of about 100# of melted down and cleaned up wheel weights, six lead bricks of unknown composition (soft) and 5 -10 # of Linotype. Is there any method besides trial and error of turning this mess into good bullet metal?
BEWARE — BEWARE – BEWARE
Before you mix any quantity of the unknown metals that you mention, be aware that even minute amounts of aluminum or zinc can completely ruin the casting properties of the metal. Before you mix those different lots of metal, take a sample of each, add enough solder to provide 2% – 3% of tin to the mix, and cast. If the unwanted metals are present you will positively NOT get filled out bullets (although there are other factors can cause the same problems).
Casting pure Linotype is very satisfying because it makes such beautiful bullets. It is not done much because of its expense and is most often used as a source of tin and antimony. Wheel weights alone or with the addition of 2 to 3 percent tin is excellent bullet metal and has the added advantage of being about the right hardness (strength) to make good hunting bullets; Linotype shatters and SHOULD NOT be used for big game hunting.
Recycling bullet metal is common and any tin burned off in the process can be easily replaced by the addition of a little sold- er.
The Importance of Good Information
The Cast Bullet Association has a great wealth of articles on alloys. Please be aware that a good deal of bad casting/alloy information has been printed in the popular gun rags in the past and continues to be. The Cast Bullet Association has been blessed with having members that are professionals in various fields and those members (like Dennis Marshall) have put to rest a good deal of misinformation that writers have spread over the years. There is so much to be learned (or corrected) that lots of reading is necessary.
The single, most comprehensive yet concise article that I have seen on bullet metals was published in the 1991 Fouling Shot, Jan-Feb issue, beginning on page 89-8.
The only control one has over the as-cast bullet diameter, using a given mould, is to vary alloy types. The higher the antimony percentage, the larger the bullet diameter. For instance: Bullet alloy diameter weight (grains)
lead .3578 215
wheelweights .3584 212
Lyman #2 alloy .3590 206
Linotype .3594 200
Sometimes trying a softer bullet – even though it will cast a slightly smaller diameter bullet, the resulting increased obtura- tion may fill the throat adequately to reduce gas cutting.
Alloy Properties and Bullet Fit
Incidentally, the resulting diameters of these bullets pushed through a given sizing die will differ also as the high alloy types have more “spring back”. When pushed through a .357″ sizing die, the Linotype bullet will be about .0007″ larger than the lead projectile.
For light target loads or those that use low pressures, lead and 2-3% tin for easy fill-out is usually all that is necessary (or desirable).
Someone on some list posted a caution about using modern wheel weights for casting but I have lost the info. I remember that apparently the new style (shiny) contain Zinc which caused some problem or other.
The “modern” wheelweights, if you mean the tape type stick-on, are not worth the fuss as they will gum up your pot beyond be- lief! As far as I know, they do not contain zinc, however.
The Problem with Zinc Contamination
What problems does Zinc cause? Is there a reasonable way to “flux it out”? Could I use them for something else (swaging maybe or pouring into a copper jacket to make FMJ…?
Zinc ruins bullet metal in that it prevents mold fill-out. It cannot be removed by home methods and is to be scrupulously avoided.
One exception; pure zinc bullets poured in straight sided molds, where fill-out is not so much a problem, shoot very well and act like FMJ bullets. They are VERY hard. Use just like jacketed bullets – no lube. My Dad gave me lots of zinc about 35 years ago and I had a good time with it.
In that same line, if you have a core mold, zinc contaminated metal should work well for jacketed bullet cores. I make .22 caliber bullet jackets out of fired .22 LR cases and use dubious alloy as cores. Corbin makes both the core molds and the dies to form jackets from .22 LR cases. It is not a complicated proce- dure and I experimented with it so that, God forbid, jacketed bullets are someday not available, I will have a source for my .22 centerfires.
If you choose to try pure zinc bullets, make sure that, when returning to lead casting, your equipment is thoroughly scrubbed, as it takes only a slight amount of zinc to contaminate your lead alloys.
I have been unable to swage pure zinc – even on my old C-H Swag- O-Matic which swages the hardest lead alloys with ease. It breaks either the handle or the bullet.
Using Linotype and Creating Defense Loads
I found a bunch of Linotype @ .50 per lb. I don’t think that this is the best, because a little too hard, alloy for .45 ACP defense use. Do you agree? Perhaps a 45% lead, 45% lino, 10% 50/50 solder might be a good place to start.
Linotype is a 475 F eutectic with 4% tin (Sn), 12% antimony (Sb), and 84% lead (Pb). It makes the best looking bullet going but is a waste of expensive tin. Alloy it with 50% lead and you will have a great bullet alloy which will cast at about 14-15 BHN and can be heat treated to about 22 BHN if desired. For non-magnum pistol velocities even that 14-15 BHN hardness is not necessary. For a softer alloy still, add more lead then bring the tin content back up with solder. Do keep your tin content at about 2%-3% though, for good mold fill-out characteristics. However, for a .45 defense load, the hardness, as relates to bullet performance on the target, is not awfully important. Velocities are too low for the .45 ACP to (dependably) deform in flesh except for perhaps pure lead in a gaping cup point configu- ration. Even then it is not be dependable unless the cup is filled with grease. I have had reports sent to me that there have been some colossal failures to expand by some of the recent- ly introduced high hype pistol bullets when fired from close range into water and water saturated paper.
Bullet nose shape and diameter is the key to bullet performance in flesh for pistol velocities. The flatter, the larger diameter the nose, the better the disruption. If there is a little metal upset, so much the better, but do not count on it.
For a succinct explanation of this get Veral Smith’s catalog. It is filled with priceless tidbits. He is:
Lead Bullets Technology HBR 62, Box 145 Moyie Springs, ID 83845 (208)267-3588
His catalog alone is an education in bullet fitting and loading.
Accuracy, Bullet Fit, and Obturation
A friend has a Webley WG, and cast some bullets of lead with (I think) 5% antimony and 2% tin, to harden it up. When we fired the reloads, they were not very good. He bought some bullets of a softer alloy, and when we shoot these, they are very much more accurate than the others (like, they all get on the target!), so even a few percent makes a big difference.
The hardness of the alloy, taken by itself, is not necessarily the controlling factor for good accuracy. It has been pretty well established by serious cast bullet shooters that fit of bullet to the revolver throat is probably the singular most important factor (other loading practices being reasonable for the type of loading being done) to accomplish good accuracy.
If the (cast) bullet is more than about .0005″ smaller than that of the throat, chances for good accuracy are diminished. This is because gas cutting of the bullet, while it is still in the throat, can destroy the integrity of the bullet and blow molten lead ahead of the bullet where it will plate the bore.
Contrary to what some shooters believe, loads that lead the bore can sometimes be cured by using a SOFTER bullet rather than a harder one. This is because the softer bullet will more easily bump up (obturate) to fit the throat than the harder one. This obturation reduces or eliminates gas cutting. The softer alloy, if not driven too fast, is more forgiving of oversize throats. See “VELOCITY REQUIRED TO EXPAND OR DEFORM VARIOUS HARNESSES” an Excerpt from “The Fouling Shot” Issue #81, Sep-Oct, 1989 “Match Wheelgun and Load Preparation, page 81” near end of this article for alloy strength as regards velocities.
The reason for the reputation of hollow base wad cutter (HBWC) as such an accurate projectile in so many guns is that its design makes use of this knowledge. The soft skirt of the HBWC easily deforms to fill the chamber throat so that there is virtually no gas cutting. Remember, the HBWC is a target bullet, and attempting to drive it too fast poses the possibility of blowing off its skirt which may lodge in the bore.
As an aside, I have found one of the most accurate and explosive .357 Magnum loads to be a reversed HBWC with a gas check placed on what was originally its wadcutter nose. This is not practical with all HBWC bullets because the nose is too large to accomodate the gas check. I believe that mine are of Star manufacture. These loads are driven hard with H-110 and W-W 296 and exhibit virtually no leading.
Your cast bullets are likely to be undersize for your Webley’s throats (a common situation) while the softer projectiles were of larger diameter and/or were soft enough to obturate enough to fill the throats adequately.
Safety Precautions and Casting Fumes
Is there any danger associated with fumes in lead bullet cast- ing? Any common methods of protection?
Lead does not begin to out gas below about 1100 degrees F so the danger is not from lead fumes. It seems that the danger from lead is not very well understood by most casters in that quanti- tative information does not seem to be available nor do we ordi- narily have means to measure quantities. Prudence is therefore the common sense answer to avoiding problems. I would not feel comfortable casting in an unvented cellar, for instance, although this has been a common practice in cold weather country and places that have a winter. Here in San Diego, where the coldest temperature is about 40 F, I cast in my open garage and feel safe doing so. As a precaution, after casting many years I decided to have my lead blood level checked. The normal city dweller is 11; mine is 5.
A couple of years ago I read an account of a bullet caster that had a dangerous experience with an unknown lead alloy that out- gassed something that caused him to pass out for a while even though he was in an open area. Some alloys such as lead plates from modern batteries are to be avoided at all costs because of the hazardous alloying materials. In the old days (late 1940’s – 1950’s) I used battery plates as nearly all my lead source.
A great deal of info is available regarding casting and alloy hazards in the pages of The Fouling Shot (now The Cast Bullet).
Back copies of The Fouling Shot are available from:
Frank Stanard, Director of Services 7418 Ridgewood Avenue Chevy Chase, MD 20815
Understanding Alloy Strength and Chamber Pressure
Excerpt from “The Fouling Shot” Issue #81, Sep-Oct, 1989 “Match Wheelgun and Load Preparation, page 81:
Correct bullet hardness for revolver target loads is about 8-12 BHN, depending upon the charge giving best bullet stability and the chamber pressure generated.
The usable maximum chamber pressure of an alloy is a function of its Brinell Hardness Number. As a rule of thumb, optimum chamber pressure for adequate obturation without leading is about four times yield strength. The conditions of firing in a revolver are more severe than in a rifle, so this figure must be taken as an absolute, though in a rifle this approximation can be exceeded to about 5 times yield if everything is “perfect.”
Within the range of alloy hardness we use for typical as- cast or heat treated bullets (from 5-30 BHN), yield strength is approximated by the BHN multiplied by 480. This means that a soft alloy of 8 BHN, such as factory swaged lead bullets will stand up to about 15,000 CUP (8x480x4=15,360), and an alloy of 12 BHN will stand 23,000 CUP.
This corresponds to the pressures generated by 4-6 grains of fast burning pistol powders such as Bullseye, 231, Red Dot, Green Dot or 452AA, which are all well suited for the .44 Spl. My favorite all-purpose alloy is a mixture of indoor-range backstop lead (mostly .38 wadcutter and .22 rimfire bullets) mixed with about 1 part in 20 of Linotype to provide some minimal tin to improve casting. This stuff makes a nicely filled out, soft bullet of 11 BHN. Eric uses a similar alloy for his gallery pistol loads. By the way, this soft alloy also shoots well in moderate .30 cal. rifle loads up to about 1500 f.p.s., and is without peer in the big bores, such as the .45-70.
The rest of this article is jamb-packed with other valuable tips for improving revolver accuracy. It is posted in an effort to convince you to become members of the Cast Bullet Association. It’s newsletter, The Cast Bullet, has more immediately usable information in it in any given issue than ALL other gun periodi- cals combined — guaranteed! A great deal of the articles apply to jacketed bullets as well as cast.
Alloy Hardness and Terminal Performance
VELOCITY REQUIRED TO EXPAND OR DEFORM VARIOUS HARNESSES
MINIMUM
TERMINAL HOLLOW * BHN VELOCITY POINTS
30-50 2400 fps NR 20 2200 NR 18 1900 NR 14-15 1500 NR 10 1400 900 fps 8 1300 800 5(pure lead) 1200 700
NR – Not recommended for game shooting because of extreme destructiveness. Good for varminting, though.
- Hollow point size and bullet nose shape affect required terminal velocity greatly, so these can only be considered approximations. Hollow points are best used with pure lead or tin-lead alloys as even small amounts of antimony cause bullet break-up. If antimonial alloys are used, do not exceed 1 1/2% antimony or 10 BHN.
Advanced Alloy Characteristics and Further Reading
The 1991 Jan-Feb issue of the Fouling Shot has an article by O.H. McKagen and Dennis Marshall entitled “On Lead-Tin Solders”, page 89-8 through 89-14. It is the best explanation of bullet alloys, their hardening, softening, time dependent characteristics (no, that bullet that you cast last week is not the same bullet that you have on your shelf today) that I have ever read. It puts into perspective the nature of a number of alloys used for cast/swaged bullets, time hardening, time softening, boundary slippage etc., in words that the layman an understand.
The resulting knowledge can be used to give the caster/swager more control over his bullets than he might have ever dreamed was possible. It also helps one to recognize errors that often appear in the glossy gun magazines when the writers presume to relate their infinite wisdom to those (us) serfs who are unread, unwashed — you know the rest.