Friday, August 19, 2016

Basics Of Bullet Casting

This article is one I found years ago. I do not know the author but it is a good description of bullet casting basics. He or she says it much better than I could. I appreciate their knowledge and thank them (whoever they are) for this article. My casting experience is limited. Burn

"The economics of bullet casting
I suggest you do this for learning and enjoyment, because the economics don't justify it. Except for some obsolete and heavy calibers, you can buy cast bullets cheaper than you can make them if your time is factored in as a cost. For example, 500 .38 special cast bullets cost about $22 at the local gun shop. And that's pretty close to the delivered price from a mail order shop. Casting, inspecting, sizing and lubricating 500 bullets ourselves is going to involve several hours of labor. Using any reasonable labor rate, it makes no economic sense to make the bullets.
Casting bullets is part of a hobby. Let's throw out the idea of valuing our time! This is fun and we can fine tune cast bullets to specific guns for better shooting. What more justification is needed?
Safety, safety, safety
We'll be dealing with molten lead alloy, as well as some other obnoxious substances (more on that in a moment). You must take care to avoid toxic fumes as well as minimize burn hazards. I do all my melting and casting outside, under a covered porch, with plenty of ventilation. I have a set of inexpensive tools dedicated to this process, and they get used for nothing else. If you have young ones around, you need to be even more cautious, because lead ingested by kids can cause harm to their developing bodies. Keep youngsters away from the casting process until they are old enough to participate responsibly. When done casting, clean up your work area so that nothing is left behind for them to get into trouble with.
Our society has demonized lead in the last thirty years. The goverment would have you believe you'll fall over dead at the very sight of lead. It's not as bad as that, but common sense is required. Wash your hands frequently, and always before you are about to eat or drink after handling lead. Avoid touching your eyes, nose and mouth while handling this stuff. If your clothes get contaminated during the casting process, change them before resuming your normal family and work routines. No reason to put other people in jeopardy for lead exposure just because it's part of your hobby.
Minimal safety gear:
• A work area with good ventilation; outside would be best
• Safety glasses (eyeglasses or range safety glasses will work)
• A pair of heavy work gloves
• A sturdy surface to hold your burner and lead pot
• Closed top shoes
Optional, but a good idea for some folks:
• Long sleeve pants and shirt
• Respirator mask
Sources of lead
Lead can be purchased from scrap yards, plumbing supply houses, and mail order companies that sell reloading supplies. However, the easiest source of lead for basic casting is used wheel weights, available by the bucketfull at any tire shop or auto dealership. Bring your own bucket, stop at the service manager's desk, and politely ask if they'd be willing to part with some used wheel weights. More often than not, they will gladly give you as much as you can carry. Some places may say no because of liability concerns or because someone pays them for the scrap metal. I've visited four tire shops in my area, all were happy to let me take as much as I felt like carrying.
Wheel weights are ideal for casting basic bullets. They contain a small amount of tin (about 0.5%), as well as antimony (about 5%). The tin makes the molten alloy flow better, and the antimony makes the alloy harder. Bullets made of wheel weights typically come out just right for moderate handgun velocities, and work well at modest rifle velocities if you add a gas check to the bullet. Casting experts have developed expertise in varying the alloys for different purposes. Specific amounts of tin and antimony can be added to create very different working properties for cast bullets, for specific uses. We'll leave the advanced metalurgy for the real experts. There are many resources on the Internet for such wisdom, and I've included a few references at the end of this article.
What you need to begin casting
The list of equipment is minimal, and actually rather primitive by the standards of our modern, digital age. After all, this process is hundreds of years old, and the equipment of yesteryear (a campfire, an iron pot, a ladel, etc.) still works.
You can buy equipment specific to bullet casting. Or you can go the economy route, as I did. The cookware section at the local Walmart provided most of my gear. Here's my list and what each item cost. As you can see, there isn't much investment to get started.
• Electric, single burner stove with variable temp control, $9
• 1 quart aluminum saucepan, $3
• Stainless steel condiment cups (used for molding ingots), 2 packs of 4 cups, $1/pack
• 10x10 aluminum cake pan, $3
• 3 pack, 10x10 aluminum foil cake pan (disposable kind), $3
• Metal spoons, six for $1
• Small ladel for scooping and pouring molten alloy (I use a Lee ladel from MidwayUSA), $3
• Fluxing material: Used candlewax, old crayons, bullet lube, pretty much anything that is wax-based will work.
• A bullet mold (more discussion on mold selection a bit later). From $16 to $60, depending on type.

Getting started
We'll start out by making ingots. While not absolutely necessary, it's a good way to clean your wheel weights, and get some practice pouring the alloy before we start casting bullets.
It is critical that you have good working space. Outside and covered is ideal. We need to avoid the fumes, and we also need to avoid having any water near our melting pot. You must make sure that no moisture comes in contact with the molten alloy. A drop of water in the molten lead can cause a steam explosion, splattering molten lead all over you and anything else nearby. Water and molten metal do not mix!
Some people advocate washing the wheel weights before melting them down. Not necessary, in my opinion. All the crud is going to come off in the metal soup when we flux it, so leave it dirty. If you do wash the wheel weights, let them dry for several days. It all has to be dry when it goes in the pot.
For basic casting, use only the wheel weights that have the steel clips. The stick-on, adhesive backed wheel weights are pure lead; too soft for modern bullets. Save them for another day if you shoot black powder and want to cast your own muzzle loader balls, or you want to custom mix alloys by adding other casting metals.
Put about 5 or 6 pounds of wheel weights in the pot and turn the electric burner on full power. Go find something to do for 20 to 30 minutes. Come back every five minutes to check the pot, but don't hang around too long. The crud on the wheel weights (road grime, tar, dog piss, etc.) will start to burn off, and the smoke is about as foul as anything you'll ever smell. Reminds me of the New Jersey Turnpike, near Port Elizabeth. If you've been there, you know what I mean. Foul.
Many casters use a lead thermometer to monitor the alloy temperature. I haven't graduated to that level yet. A good lead thermometer is $30 or more, and being the cheap SOB I am, I don't want one. The 1100 watt Walmart electric burner needs to be left on high to keep 5 to 8 pounds of wheel weight alloy in liquid form. I just set it there and leave it. It's just hot enough for eiffcient pouring. For more advanced casting with harder alloys like Linotype (printer's lead), a stronger heat source is needed.
Once the alloy is molten, the steel clips and a whole lot of other crud will be floating on top of the mix. Skim it off with a spoon. Dump the skim into one of the baking pans. Remember, all this stuff is very hot, so handle it with care. Don't put it in the trash until it has cooled off. Once you've taken the debris off the top, you are left with a dirty soup of liquid metal, somewhat silvery in color, but with some black, ash-like stuff floating around. Those are impurities we will take out with flux.
Sounds far more complicated than it is. Simply put, we're dropping some wax (or bullet lube, or fluxing compound) into the mix. It's role is simple: Make anything that is not lead alloy stick to the flux material so we can easily scoop it out. Take a few wax shavings, drop them in. It will smoke, and may even burn. Wait until the smoking stops, then slowly, but thouroughly, stir the mix with your spoon or ladel, scraping the sides and bottom of the pot. All of the gray, black, flakey crap that forms at the top, we want to try and corral and skim off. You should be left with nice, silvery looking molten alloy when you've finished fluxing. Don't drive yourself nuts seeking perfection on this step. There will always be some crud left on top of the mix. But it should be minimal. More will show up later, and you can flux again anytime you feel it is worth getting more crap out of the mix. Small amounts of impurities won't hurt the mix, but we don't want chunks of garbage in there, either.
Pouring ingots
With nice, clean wheel weight alloy in liquid form in the pot, it's time to pour some ingots. Take the stainless steel condiment cups and place in one of the cake pans, on a level, sturdy surface. Make sure that whatever surface you use will stand up to the heat. The alloy is somewhere between 625 and 700 degrees, and will apply considerable heat through the cups to whatever they are resting on.
With your gloves on, pick up the pot and pour the molten alloy into the cups, until they are about 2/3 full. Pour carefully to avoid spills and splashes. Let the cups sit undisturbed for about two minutes, so the alloy can harden. After that, you can pick up the pan and move it if you are concerned about where it is resting. I usually put it on the ground (concrete) after the lead has returned to solid form. The ground helps dissipate the heat more quickly.

After about ten minutes of cooling, with your gloves still on, turn the cups over and gently tap them. The ingots fall right out. They will still be hot, and so will the cups, so be careful handling them. After about 20 minutes, they are cool enough to handle. Here's what you get:
Now we have nice, clean, nearly pure lead/tin/antimony alloy ingots that are perfect for casting bullets, in a handy size, easy to store, and easy to melt. A pound of nicely cast wheel weights goes for about a buck on eBay, so if you really want to go to town, you can sell your excess ingots for a little cash.
We're ready to cast bullets.
Casting bullets
You'll need one or more bullet molds, based on the caliber, weight and style of bullets you like. Bullet molds are available from many online sources like MidwayUSA, Brownells, Midsouth, etc. Used molds can be found on eBay. There are two major types of molds: Aluminum and iron. I have several Lyman iron molds, and they work very well. I also have some Lee molds that took me a while to get the hang of; once I mastered using them, I started to produce some nice clean bullets. Aluminum and iron have different casting properties and dictate slightly different approaches to casting, and involve a small learning curve. The molds commonly come in single, double, quad and six bullet configurations, which impacts how quickly you can cast bullets. Some of the bullets will be improperly formed rejects. They just go back into the pot for another try. The molds have to heat up to produce good bullets, so it may take some practice casts until you get good bullets. Lee molds are inexpensive, typically less than $20 for a two cavity mold, and should last for 10s of thousands of bullets. The iron molds, properly cared for, can be passed to your grandchildren. Unless you abuse them, they don't wear out. Lyman sells rebuild kits that contain washers and screws, for replacing the parts that most likely will wear out before the mold.
Each mold needs a handle (some molds come with handles, others require they be purchased seperately). The sprue plate is a hinged plate with a hole for each mold cavity, through which the molten alloy is poured. When the alloy has solidified, the sprue plate is opened, which cuts the excess lead from the base of the bullet. The mold is then opened and the bullets should fall out, or fall out with a gentle tap from a block of wood. It's best to have a piece of cotton cloth for the bullets to land on, or the aluminum foil bake pans can be used. The bullets are just below molten temperature when they come from the mold, so they are soft and can be dented easily. Some casters drop them into a bucket of water (with all of the safety caveats that come with such a practice...remember what I said about water near the melting pot). This is called quenching, and produces a considerably harder bullet than just air cooled bullets. Most shooters will be well served with air-cooled cast bullets, but if you want harder bullets, quenching is an easy way to get them using wheel weights.
The process isn't much different than the ingots we just poured. Follow the mold manufacturer's directions for mold prep, which may involve lubricating parts of the mold, and smoking the mold with the smoke from a lighter or matches.
When your lead alloy is molten, scoop some into your ladel and pour it into the mold until a puddle forms on top of the sprue hole. Wait until it hardens, about 3 to 5 seconds, then open the sprue plate and drop the bullets out. Sometimes a tap from a wooden dowel is needed to free the sprue plate or get the bullets to drop out of the mold. With some experience, you'll learn how to efficiently do all of these steps. Close the mold, pour more alloy in, and keep it up until you have the quantity you want. Keep an eye out for poorly formed bullets, which could indicate problems with alloy or mold temperature, or foreign debris in the mold. The mold has to heat up to a good working temperatue before you get consistent results, so your initial casts may produce quite a few rejects. You can put those back into the pot. Be careful not to splash molten alloy on yourself or your work area. A few minutes on prep will minimize the number of rejects.
Sizing, Lubricating
After casting, one or two operations remain. We may have to size the bullets. This depends on a couple of things: The size of your gun's bore, and the size of the bullet the mold casts. If you can fit a bullet into a case without bulging the case, it does not need to be sized. For example, the .314 caliber wheel weight bullets from my Lyman 311495 mold fit into a flared .303 British case. My Enfield's bore size is .312. A cast bullet that is .001" to .002" greater diameter than the bore is good. If the bullet is undersized, the bullet may not fully engage the rifling, resulting in poor accuracy. If the bore is too small, the bullet may generate excess pressure and leave lead in the barrel. Lee makes inexpensive sizing dies that cost about $12/caliber and work with any reloading press that takes standard dies. Lyman, RCBS and others make more sophisticated, one step lubricating/sizing tools, and these are often preferred by casters who want the finest. The Lee dies work. The sizing step is also good time to put gas checks on bullets intended for high velocity loads. A gas check is a small metal cup that fits around the end of the bullet. It is typically press fit at the same time the bullet is pushed through the sizer die. The gas check protects the bullet from the high pressure and heat of the powder burn, and reduces or eliminates barrel leading that would otherwise occur at high velocities.
Lee sizing dies come with a liquid bullet lube that is easy to apply. You put the bullets in a plastic tub, add the lubricant, and tumble the bullets around until they are coated. You then set them out on wax paper overnight to dry. Cast bullets must be lubricated, or they will leave lead in the barrel of your gun, making cleaning a real bear.
I've experimented with different loads, bullets, and lubrication, and I've gotten some of the tightest groups I've shot with my guns.
That's basically it. Advanced bullet casting is simply additional detail or processes on top of what I've described. Using the above info, you can experiment and custom match bullets to your guns for excellent accuracy. Or you can just make a big pile of bullets that are accurate enough to kill tin cans at 30 yards. As with other aspects of shooting sports, what you get out of it is up to you.
*Edit: Since writing this article, I purchased a "previously enjoyed" Lee bottom pour lead furnace. Well worth the investment. It greatly eases the bullet pouring process. I still use the saucepan and hot plate for making ingots, and those tools are still adequate for making bullets if you are on a strict budget."

Again I thank the author for this brief "how to". Prices may be a little higher as this article is from about 2008 I think.

Semper Paratus
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