Reloading Basics - Bullet Casting Part 4
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- Last updated: 29/12/2020
So before getting into preparation and melt-down, just a quick reminder, before you turn on the pot and start melting alloy, please revisit the previous article on safety.
Your new mould should be completely cleaned, per the manufacturer’s instructions, to ensure all protective coatings and residues are removed. The first step is to get the pot filled with good clean alloy and set the thermostat to maximum, to get it melting.
Although the ingots melt, and the alloy will settle in the pot, do not ‘stack’ them so high that they stick above the rim of the pot. You can add another one, once the first ones start to melt, and this is much safer than having excessive hot ingots toppling off the pot. Place your mould on the top of the pot, safe and stable, so that the blocks can be preheated, but not the wooden handles.
Once melted, add your chosen fluxing material and stir the pot thoroughly, not too vigorously though, as this might cause molten alloy to splash out of the pot. Fluxing will bring dirt and crud to the top and it should be skimmed off and disposed of. At this point, the thermostat can be turned down. You want to maintain the alloy at a temperature where it flows nicely from the pot, like a fine oil, and there is no smoke or discolouration on the top of the molten metal. On a Lee Production Pot, setting the dial to six seems to work well. Pour alloy from the pot into a ladle a few times to see how it flows and also to get used to using the pouring spout. Once you have your pot hot, and you are happy with how the pouring spout operates, you are ready to start filling your mould.
By now, your mould should have heated up considerably, but it is probably not up to the optimum temperature for casting perfect bullets. The cavities will only be brought up to full operating temperature after they have been filled with alloy a few times. Incomplete and wrinkled bullets indicate a cold mould and you will have a fair few ‘rejects’ to start with, which should be re-melted.
Ensure that the sprue plate on top of the mould is fully closed so that the holes in the plate are aligned centrally above the cavities. Next, positioning each hole in the sprue plate directly below the nozzle on the melting pot, in turn, lift the operating lever on the pot and fill the cavities. It takes a bit of practice to get the flow rate right; too fast and lead will spread over the sprue plate rather than flow into the mould, too slow and it will fail to fill the cavity and just hardens on top. Practice makes perfect!
The alloy has to fill the mould entirely and displace all of the air in the cavity. A relatively ‘fast’fill ensures that it gets into all of the edges and recesses, producing good sharp edges on the finished bullets. Having the correct distance between the sprue plate and the nozzle on the pot is important, around 1” seems to work well.
It is best to slightly over-fill the cavities so that there is a small puddle of alloy on top of the sprue plate, over each countersunk hole. This ensures you get a properly filled bullet with no voids or concave bases.
After allowing the alloy to set for a few seconds, you then knock the sprue plate open using your wooden mallet and open the mould. The bullets should fall free on their own, but they do occasionally need a bit of help. Tap the handle hinge of the mould, not the blocks, and they should then be allowed to fall onto a soft cushion.
You should not expect your first bullets to be perfect or useable because they never are. There are two factors at play; your own procedure (which needs to be practised and perfected) and the need to ‘run-in’ your mould. While the first of these factors is down to you, the second is something that is the subject of endless debate. Online you will find hundreds of suggestions on how to run in your moulds, to speed up or improve the process. The only one that seems to work, is to just keep casting until you get decent bullets, it can be time-consuming but if you persevere you will eventually get there.
As you get used to casting you will find that you get into a routine and your production rate increases. You must get the speed right because it will affect the quality of what you are producing. The correct rate will produce good quality bullets without overheating the mould.
Bullets can start coming out of the mould with a ‘frosty’ appearance, and while this has no detrimental effect on how they perform, it does indicate that the mould is getting too hot and is at risk of damage. To cool the mould, all you need to do is leave it, empty and open, on the bench for a couple of minutes. Don’t be tempted to dip it into water! When bullets start to come out clean and shiny again then the mould is back to the right temperature.
The important things to remember when you start casting is that it takes a while to get good results, and not to give up. Getting your procedures right takes practice, and sometimes you might have to call it a day because you cannot cast a decent bullet. Just walk away and try again another time. Once you learn to get it right, with useable projectiles falling from the mould every time, you can maybe introduce a second mould into the process to potentially speed up production or make a second type of bullet. Casting your own saves a lot of money compared to buying projectiles, and it is another interesting and rewarding element of reloading, so give it a go, but stay safe!