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From Ingot to Target: A Cast Bullet Guide for Handgunners©
Chapter 2: Casting 101
Shooters who cast their own bullets add a whole new dimension to their handloading endeavors. As a bullet caster, you will open new doors to experimentation with ammunition and you will become your own bullet supplier. This chapter will deal with the physical details of casting bullets.
The old phrase “the best place to start a task is at the beginning”, is in a way, humorous, but also very true in learning the techniques and the science involved in casting bullets. Safety of the bullet caster is of utmost concern to the authors and it is at this point that you are reminded to please study the chapter on safety before undertaking the melting or pouring of lead alloy. Assuming you have studied the chapter on safety, we will proceed to learn the art and science of casting your own lead alloy bullets. The chapters following this one will go into detail about the various bullet alloys, bullet hardness, bullet lubes, to gas check or not to gas check, and fluxing the alloy.
Cleanliness and purity in the alloy you use and a good clean mould are paramount to making good bullets. Any volatile solvent, even in the form of vapor, will prevent complete fill-out in the cavity and no useable bullets can be made until the mould is completely free from any petroleum distillates or other solvents.
If you are a beginning caster and are starting with a brand new mould, you may have a patience-taxing task ahead of you; please do not lose heart! Breaking in a new mould will net more than just a good casting mould, it will give you a life-long companion for your shooting activities. Mould break-in involves oxidizing the cavity interiors. This is accomplished first by pre-heating the mould on top of your melting pot (provided you have a large enough ledge on your pot to safely hold the mould with it’s handles), and second, by casting bullets in the mould. The time you spend pouring bullet alloy into the cavities of your new mould will give you experience in the techniques of pouring, controlling the alloy, learning how it reacts to temperature changes, and the effects that the pouring rate and temperature have on the quality of the bullet.
Working with good equipment will make it easier for you to learn the skill of bullet casting. High quality expensive equipment is not mandatory for casting good bullets, although it certainly makes learning easier for the beginner and lessens the likelihood of frustration. As our good friend John Taffin likes to say, "Cheap equipment is too expensive!". Good tools make the job go easier, and will provide a lifetime of service.
Your first need in getting started will be a very well ventilated and dry area in which to set-up your equipment. No water can be allowed to come in contact with the molten alloy. A fan may be necessary to move hot and contaminated air away from the casting area. It is best to situate the fan so the moving air flows over the top of the pot and does not blow directly on it.
A good quality melting pot will be your first large investment. Whether the pot is a ladle pour or a bottom pour, it should have a temperature control on it calibrated in degrees (although this calibration scale may not be all that accurate, it gives you a means of reproducing those conditions that work best for your particular equipment). If you choose a bottom pour pot, it should have a rugged, adjustable pouring valve. If you choose to use a separate heating source and melting pot, it will be necessary to purchase a casting thermometer so you can keep track of the alloy temperature (these are available from a variety of sources and are affordably priced).
Your next investment will be a mould suitable for the caliber you wish to supply bullets for. Generally it is easier to cast bullets of .38 caliber or larger and of short, simple design. Learning the skills of obtaining good quality bullets will require much less effort and concentration on your part by starting out with a mould designed to cast bullets designed for handgun use. The beginning caster will learn how to regulate the flow of the alloy to achieve complete fill-out of the cavity for high quality, uniform bullets. You will become familiar with the feel of the mould/handle assembly in your hand as the alloy fills the cavity and the sprue countersink. Each type of cavity and each size of sprue hole has a particular flow rate and temperature where it produces the best results.
The next two purchases you make will be the alloy and flux you intend to use. As mentioned earlier, separate chapters on fluxing and the properties of the various alloys follow this one and you will need to study those before doing any casting or making any purchases.
The next two items are ones you most likely already have. You need an old towel folded up so the still hot and slightly soft bullets will have a soft surface to fall upon ejection from the mould. The other item is a hardwood stick or piece of 1” dowel about 12” – 14” long. The length and diameter are not critical as long as you are comfortable using it. This hardwood rod will be used to either push or tap open the sprue plate after making a cast in the mould. A piece of handle from a rake or hammer can work well for this purpose and may be something you already have in your garage or shop.
The last remaining item will be a scooper/stirrer you can use to stir in the flux and scoop the sludge from the top of the melt. A wooden handle is very valuable here as this tool routinely gets very hot in use. Do NOT use aluminum or anything containing zinc in your alloy. Also do not use any kind of eating utensil, as it will be heavily contaminated with lead in use and might get mixed back in with the silverware, poisoning whomever eats with it.
Now that you have accumulated all of the necessary tools and equipment and have studied the pertinent casting information in this book, you are ready to heat up the pot, warm the mould blocks which are assembled to their handles, and start pouring bullet alloy into your mould cavities.
Just a reminder before you start heating up the pot: REVIEW THE CHAPTER ON SAFETY FIRST!
Make sure the mould is completely clean. Alcohol can be used for a final cleaning (and is good for removing petroleum distillates and other solvents). Most of the solvents used for electrical and automotive brake lining degreaser work well for initial cleaning and removing preservatives and cutting oil residue left in the mould from the manufacturer.
Assuming you are using an electric melting pot, plug in the power supply cord as per the manufacturer’s recommendation. Set the thermostat to about 750o. While the pot is warming with the ingots of clean bullet alloy resting inside the pot, place the complete mould on the ledge of the pot so the blocks themselves are actually on the ledge and NOT the wooden handles. This will allow the mould blocks to slowly preheat.
Once the alloy in the pot has melted, it will need to be fluxed, stirred, and later skimmed of the dross (crud) that has floated to the top. After the fluxing operation is concluded, you are then ready to take hold of the wooden end of the mould handles and start filling the cavities with molten bullet alloy from the pot. If you are using a ladle, place the ladle over the pot and begin allowing it to heat, by very slowly lowering the ladle into the melted alloy. When fully submerged, leave the ladle head in the alloy for a couple of minutes to thoroughly heat soak it to the same temperature as the alloy. Go ahead the remove the ladle full of alloy and pour the alloy back into the pot using the pouring nozzle. Repeat this process a few times to get used to the feel of pouring through the nozzle and seeing how the alloy behaves while being poured. The lead alloy, when at the correct pouring temperature, will flow much like water or very thin oil. Now you are ready to pour lead alloy from the ladle into the mould cavities.
If you are right handed, it may be easier to hold the ladle in your right hand and the mould in your left. Turn the mould top face (sprue plate) vertically so the sprue holes face to the right. Now place the ladle's pouring spout (or nozzle) up against one of the sprue plate holes with the ladle pouring nozzle firmly pressed to the sprue pouring hole, and turn both the mould and ladle together as a unit upright, thereby causing a portion of the alloy in the ladle to flow into and fill the bullet cavity in the mould. If you have a two-cavity mould, repeat this process with the second cavity. Place the ladle back in the pot. Wait a few seconds for the alloy in the sprue hole countersinks to solidify (this metal is commonly referred to as "the puddle"). With your wooden rod, push or knock the sprue plate open. Swing the plate fully open. Open the mould and let the bullets fall onto the soft towel you prepared. It may be necessary to tap the handle hinge to eject stubborn bullets. Repeat this whole pouring procedure as many times as needed until you are comfortable with the entire process. As you cast with the ladle you will see a dull looking sludge begin to build up on the ladle and inside the pot. This needs to be fluxed and stirred back into the melt. Now that you have some experience in pouring bullets, you can refine your technique by learning to pull the ladle back enough after the cavity is filled, to leave a puddle of alloy in the sprue countersink. Filling the countersink prevents voids in the bases and concave bases. Both conditions invite leading and inaccuracy caused from improperly filled-out bullet bases.
The process with bottom pour pots is essentially the same as with using a ladle except that the alloy flows directly from the bottom of the pot through the nozzle. A valve to which the handle is attached controls the flow. The handle is mounted toward the front of the pot for easy access.
Some casters have trouble casting good bullets with a bottom pour pot. The only difference between the ladle method and bottom pour method is that the bottom pour pot has the entire vessel full of alloy sitting on top of the nozzle. This condition is generally termed head pressure. Only experience wrought through trial and error will teach you how best to adjust and regulate the flow of alloy on a bottom pour pot for complete fill-out with each design of mould cavity you cast bullets in. Normally, higher temperatures are required when using a bottom pour pot. It may be necessary for the pot temperature to be set as high as 850o. It is recommended that a layer of charcoal or sawdust be placed on top of the melt to protect it from oxidation. This subject is discussed in the fluxing chapter. Keeping the pot only half full may also help eliminate some of the fill-out problems and render the regulation of flow easier to adjust and less sensitive to the technique of the caster. Whether using a ladle or bottom pour casting, the flow of alloy into the cavities of the mould has to be sufficient in volume and pressure to adequately fill out the cavity. You may need to develop a technique of rocking the mould away from the pouring nozzle ever so slightly just as the cavity comes to near full. This allows any air to escape from the top of the cavity during the critical base fill-out phase and it makes it easier to leave a full size sprue puddle. It may be necessary to have a slight air gap between the sprue hole and the nozzle. The amount of gap will vary from one mould to the next and can only be determined by experimentation. Different moulds have can have differing "tastes" in terms of how they "prefer" to be fed: some cast best with a half an inch of free fall for the alloy below the pour spout, whereas others (especially HP moulds) may perform best when "force-fed" (i.e. the mould held directly against the pour spout so the full force of the head pressure helps to force the alloy into the cavity). Recording the settings and adjustments for each mould may save you much set-up time in future casting sessions. Mould guides are available from the pot manufacturers for most of their bottom pour pots. Always fill the sprue plate countersinks with a puddle of alloy after the cavity is full to allow for any shrinkage as the bullet cools. Keep your pour constant and fill both the cavity and the sprue in one continuous smooth motion. Experience is the best teacher in learning these skills, and the more you do it, the better caster you will become.
Do not expect your first bullets to be shootable. You will be very disappointed if you think your new mould will make perfect bullets the first time out. They WILL get progressively better with time (and practice), and soon you WILL be casting perfect bullets. Bullet casting is both fun and profitable because it is something you do for yourself. Relax and enjoy doing it and don’t demand too much from yourself at first. As you progress further along with your casting practice you will notice that your bullets will improve in quality and appearance. This is due to the mould warming up and breaking in and improvements in your skills as a bullet caster. Under normal circumstances once a mould is broken in, it stays that way. Our learned skills and abilities are pretty much the same way. Once learned, they are not quickly forgotten.
Bullets that come from the mould wrinkled, not well filled out, are bright and shiny indicate either a too cool mould or alloy or both. When bullets become frosted and possibly eject stubbornly from the mould, the mould itself is too hot. Moulds that have small cavities and large blocks may need to be placed on a warm hot plate until they begin casting properly. You may need to do this occasionally throughout the casing session. Moulds with small blocks and large cavities may need to be set aside for brief periods to cool throughout the casting session. Advanced casters sometimes cast with two moulds alternating between the two to keep them at ideal operating temperatures. If the mould has a tendency to overheat, a fan can be located to blow on the mould while you are ejecting the bullets. NEVER, EVER, PUT YOUR MOULD IN WATER WHILE IT IS HOT! The mould will be warped beyond repair and steam and hot water may scald you.
Bullets with unfilled bases or air pockets may need a bigger sprue puddle. If the bullets are frosted, you will need to cool the mould slightly and turn down the temperature setting on your pot to about 50o – 100o. Bullets that show a cold mould condition will require the alloy temperature to be increased by 50o – 100o and more casting with the mould to bring it up to efficient operating temperature.
The following paragraphs are a brief summary of what we have covered in this chapter and can be used as a quick reference.
1. Safety is the primary concern when working with molten metal. A ventilated workplace is mandatory. Make sure the type of ventilation method you choose, pulls the harmful vapors and hot air AWAY from you. Always dress yourself in suitable protective clothing, such as closed top work boots, leather apron, gloves, and face protection before the alloy melts. NO WATER should be allowed anywhere near the casting area. Water coming in contact with molten lead will cause a violent explosion.
2. Pre-heat the mould on the large ledge at the top of the pot. Cast bullets for awhile to finish warming the mould.
3. Shiny, wrinkled bullets indicate a cold mould. Keep casting bullets until the mould is up to temperature and/or turn up the pot temperature 50o to 100o.
4. Frosted bullets indicate a too hot mould. Allow the mould to cool for awhile and/or decrease the pot temperature 50o – 100o.
5. Wrinkled, poorly fill-out bullets coming from a hot mould indicate petroleum distillate in the mould or on the sprue plate. If the mould was thoroughly cleaned before casting was begun, the heat from the alloy should eventually remove the petroleum vapors with further casting. This will be obvious if the quality of the bullets improves with further casting.
6. An adequate flow of lead has to be maintained while the cavity is filling and to also fill the sprue countersink. Alloy has to be forced into all areas of the cavity to make a fully formed bullet. Head pressure in bottom pour pots can only be regulated by the level of the lead in the pot. The flow is regulated by the adjustment at the handle that limits the amount that the valve is opened. Too much head pressure accompanied by overheated alloy can actually force lead into the cavity with such force that it causes bullets to stick in the cavity and will also cause fins on the bullet where the lead has flowed out into the vent lines. Sticking bullets will require using the wooden rod that you use to open the sprue plate with, to whack the hinge area of the handles to jar the bullet loose from it’s stuck position in the cavity. If the alloy is at normal casting temperature and the bullets are not filling out, try either increasing or decreasing the rate of flow at the nozzle. And record your settings for future set-ups.
7. If the sprue plate swings back over any part of a bullet's base, it will prevent that bullet from falling freely from the cavity.
8. Drop the bullets from the mould onto a soft towel-like surface to prevent damage to the still hot and somewhat soft bullets.
9. SAFETY FIRST!
Before the bullets can be loaded and shot, they must be lubricated and sized. Several manufacturers of casting equipment offer excellent sizer lubricators. The basic lubrisizer unit is fitted for interchangeable sizing dies and nose punches. Study the chapter on determining the correct size bullet for your application. Once the correct bullet diameter has been determined and the die and nose punch has been acquired, you are ready to fill the lubrication reservoir and ready the device for use. Follow the manufacturer's directions for installing the die, nose punch, and filling the reservoir. For flat-nosed bullets, a universal nose punch can be used, which insures that the bullet will self-center in the sizer die.
Some bullets require the use of a gas check. So long as the gas check shank of the bullet fits the gas check, the check can be placed on the shank with the fingers before placing the bullet on the plunger of the die. A separate section on annealing gas checks is included in Chapter 10.
Once the lubersizer is set-up and ready for operation, you are ready to set your first bullet on the sizing die, lower the operating handle and push the bullet down into the die. For the Lyman and RCBS style lube-sizers, turning the handle counter clockwise on the lube plunger screw pulls the lube plunger into the lube changer and forces lube through the holes in the die and into the lube grooves in the bullet. It may take several cycles of lubricating bullets to bleed all the air from the chamber and die. Air pockets in the lubricant chamber and die will result in incomplete filling of the lube grooves. On occasion, portions of lube grooves will not want to fill and will require cycling the bullet back into the die with lube pressure applied on the die to fill in the vacant area in the lube groove. It may not be necessary to tighten the screw any further if enough pressure is already applied. Most of the time, passing the bullet back through the die once will be adequate enough to fill in the groove with lube. The die has holes drilled through it at intervals to allow the lubricant to pass from the chamber of the lubersizer into the interior of the die. With handgun bullets it is a fairly easy matter to align the grease groove(s) in the bullet with the holes in the die by adjusting the depth stop located at the bottom of the lubersizer. With most handgun bullet types when the grease groove in the bullet is aligned with the grease hole in the die, the groove will fill with grease on the first pass. Bullets with multiple grooves will have the grooves filled as the grooves pass by the holes in the die on the way down into the die and on the way back. Now that your first batch of bullets are lubricated, sized, and/or gas-checked, the lube chamber plunger screw needs to be backed off about one full turn. This prevents grease from bleeding past the die plunger and from between the die body and lubersizer bore. It also relieves pressure from the internal parts and body.
Backing off the screw between uses is also important, if the tool is going to sit unused during seasonal changes where the weather passes from the cold of winter to the heat of summer. Bullet lube expands as it warms. As a result, excess pressure can build inside the tool and crack the housing of the pressure chamber ruining the tool. Heaters are available for your lubersizer in the event that you want to use a hard lube that requires heat to flow properly. Always remember to back off the screw BEFORE using a lube heater. A light bulb placed near a cold tool can warm overly stiff grease so as to make it more fluid to better fill the bullet grooves. Pressure to the screw should only be applied AFTER the lube is fully warmed. If pressure is applied before or during the warming process, excessive pressure can build in the tool and crack the housing. During the lubricating process it will be necessary to maintain enough grease (lube) pressure to fill the grease grooves of the bullet and at the same time not to allow excessive pressure to build that will force lube between the die plunger and the bullet base. With combinations where the bullet is slightly smaller than the die lube will leak around the bullet. Other than being messy and wasting lube this is not a problem as long as the grease grooves are being filled. As in the skill of casting, lubricant pressure regulation will be learned through the experience of operating the tool.
Some bullet designs have a smaller front driving band than the bullet body. With such designs it is essential that you do not allow the bullet to go too deeply into the die. If the undersized driving band of the bullet is allowed to pass below the lube holes in the die, lube will push out into the void and make a mess, which slows production and wastes lube.
Moulds that are not made properly or are out of adjustment may cast slightly out of round bullets. For handgun use this is not generally a problem. The authors of this book have shot surprisingly tight groups from handguns shooting bullets up to .009" out of round. In some cases, no difference in group size was detected between groups shot with perfectly round bullets and these out of round bullets. In other cases, this asymmetry can make a tremendous difference. The only way to know for sure if out of round bullets will have an impact on your shooting, with your gun, is to shoot them and see (adjusting an out of round mould is addressed in more detail in the “Idle Musings“ chapter). When sizing bullets that are slightly out of round, the only noticeable effect will be that of varying depths of crimp and lube grooves. One side will have normal depth grooves and the other side will have more shallow grooves and the variation in depths will depend on the amount the bullets are out of round.
Occasionally, a lubersizer will leave the factory with the bores for the ram and die slightly offset from one another. If you happen to obtain one of these units, please do not attempt to repair it. Return it to the manufacturer for a replacement. It is easy to determine if the unit you are using has offset bores. The bullets you size, no matter how perfectly round they come from the mould, will always be sized heavier on one side than the other. Normally, lubersizers are perfectly made and will last most folks an entire lifetime.
The care you give your equipment both while using and in storing it will determine how well it performs and how long it will last. The modest investment of a bullet mould and a lead pot can provide you with a lifetime supply of bullets.
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