Hello, my name is Tim Malcolm. I am a custom gunsmith servicing the members of this board and the United States as a whole.
I was taught to cast by my father who was/is a bonafide rocket scientist, an avid boolit caster, and a very proficient marksman (although he is unable to do so now and lives vicariously through me.)
The first cast bullets I ever shot were H&G #34 230gr RN 45 caliber. I would whack them with a stick to knock over my GI Joes.
The first firearm I cast for was a Pedersoli Confederate Navy 44 caliber BP revolver. I mowed lawns and scraped together the money to buy it from Cabellas for $79.95 and it came with a kit. I was 14 years old at the time. I convinced my mother to drive me to the local Kings outdoor supply where I bought a Lee round ball mold. I found out real fast that COWW or COWW/Linotype (dad had plenty) were way too hard to load in my pistol, so I got some soft lead from somewhere and started casting. Little did I know that this would be the beginning of a lifetime pursuit of the silver stream. All my bullets were cast over a Coleman stove with an RCBS ladle (which I still have and use).
I ended up acquiring many different firearms over the subsequent years several of which I made myself, and casting for all of them.
I wasn’t born with a ladle in my hand, but I came pretty close.
By far, shooting cast bullets accurately in rifles has been the consistent theme of my life. It’s what I think about waking up, going to sleep, and it’s what I make a portion of my living doing. The accurate bullet is a very enticing corrot that some men will follow from the desert to the high mountains, and I’m here to tell you that I have snow in my collar, and sand in my shoes!
Those are my credentials, and who I am.
I would like to tell you how I cast excellent bullets, if you will lend an ear for a moment.
A good bullet begins with a good alloy, and an excellent bullet begins with an excellent alloy. I consider a good alloy to be small batches of COWW, or range scrap. I consider an excellent alloy to be something that you can reproduce indefinitely with a high degree of accuracy (mix of the metals) , which lends itself to consistent casting of bullets. In order to have an excellent alloy, you must have a mix that compliments itself well, and casts beautifully. Alloys that do this are Lyman#2 (90/5/5 by percent), Linotype(84/12/4 by percent), or COWW + 2.3% tin(95.6/2.2/2.2 by percent). These alloys are predictable and forgiving, which is why they are so poplar, and have been since the dawn of boolitry.
Once you have an excellent alloy, you must have an excellent mold. Excelent molds are what we do here at cast boolits. We have access to the most superb bullet molds in history, and I dare say the people of this forum are making sure to take advantage of it. (how do you know you’re a cast booliteer? When you’ll give up cigarettes so you can afford to buy custom molds every month instead! LOL!)
There are many excellent molds available today, but in my opinion, there are none who rival NOE and Accurate molds. There is simply nothing better that has ever been made in history (not even Hensley and Gibbs).
After acquiring an excellent mold and an excellent alloy, you might sit down, plug in your pot and start casting and not be very pleased with the results. You see wrinkled bullets, frosty bullets, dented bullets, and bullets with pockets in them etc etc etc.
You bought all the right tools, and the right material but you got lousy consistency.
You would like to improve on that because not only did your bullets look terrible, they shot about as pretty as they look.
The first thing to do is to take a broad stroke and change a few basic things that will put you in a good place to get started casting well. All of these things are written about at the bottom of the page in the LASC link. But just to give you the high points as I see them, here is a list of basic things you can do to get started down the straight and narrow IMHO:
1. Use a thermometer. Heat your alloy to a spot roughly 100 degrees hotter than melt temperature (that place where the lead first turns liquid and holds temperature for a while as it makes the transition).
2. Use a hotplate to warm your mold.
3. When you get ready to fill the mold, prime the spout of your pot (if using a bottom pour pot)
4. When you pour, notice where you hit the sprue hole. Some molds like the alloy to be shot straight into the hole, and some like the stream to clip the edge of the hole. Whichever you choose, try to do it the same way each time.
5. When the first cavity is filled, pile up a puddle on top of it about the size of a quarter, stop the pour, move to the next cavity and repeat.
6. Start counting “one onethousand, two onethousand” etc as soon as you shut off the stream on your last cavity filled, and watch the lead puddles on top of the mold. At a certain point, you will see them freeze over. That event needs to happen 3-4 seconds after you stopped pouring. if your sprue took more than 5 seconds to freeze, you need to slow down. If your sprue took less than 3 seconds to freeze, you need to speed up.
7. After you open the mold, look at the bullets. If they are shiny, you need to go faster. You want a nice grey appearance with sharp lines and maybe just the faintest bit of the vent lines showing as tiny dots on the sides of the bullets.
8. Use a soft faced object to open the sprue plate the very instant it freezes. You do not need to whack the snot out of it!!!! All that is required is a few sharp taps. This creates a very flat base, and does not stress your mold. My father told me to use a piece of oak dowel with a 4” piece of garden hose pushed over the business end of it. I use a small rubber hammer.
9. When you go to open the mold, do not just wrench it open. Hold it shut tight, and give the hinge bolt on the handles a good sharp rap with a rubber hammer. Be careful to hold the mold shut tight when you do this to avoid damage. Now start tapping the hinge bolt lightly as you open the mold. If any bullets stick, give the hinge bolt another good sharp rap with the rubber hammer but this time with the mold wide open so the blocks cannot clash together and cause damage (seriously, if you've never tried a rubber hammer, you don’t know what your missing. It has a kind of “jiggle” to its strike that coaxes bullets from their beds very convincingly).
10. After the bullets drop, and before you fill the mold again, there is a certain amount of time you must wait to keep your mold from getting too hot. You have to keep it consistent. Some mold/alloy combinations need 3 seconds, some need 15. It’s up to you to figure out which.
So there are the basics of how to cast good bullets. That’s a lot of info and is about like trying to ride a bike while playing the violin till you do it a few thousand times, but what if you've got that all down pat, and you’re still not happy with the results?
Allow me to show you a method that I developed with help from sgt.mike, by which you can refine the above information to an exact process.
I use bell curves to teach me where I need work, and when I make a change, to show me whether or not it was a positive change, and it works exceedingly well for this purpose.
What’s a bell curve you might ask? It’s simply a way to use your digital scale to plot your proficiency, and literally plot it with the bullets you cast.
Here is an example:
(Can't attach any more photos. See the bottom of the post.)
This is done by simply lining up all the bullets of a certain weight in a row, in .1gr increments. It’s easy to do and teaches you faster than anything else I have ever tried. I wish I had thought of this years ago, because I wasted a lot of time not getting instant feedback from my pot. As they say, I was “close but no cigar”. It turns out that almost any defect in size, shape, mass, or diameter of your bullet can be sensed by our ultra-precision digital scales. Feel free to test this. Take a bullet and put it on your scale. Tare the scale to the bullet. Now file just a little bit off the nose and see how much it takes to make your scale read -.1gr. Like I said, it really doesn’t take much.
The only thing the scale can’t detect is the appearance of your bullets. Everything else has an effect on the weight. That’s why I pay attention to bullet weight first and foremost, after learning how to cast a good looking bullet with no wrinkles, sharp bands, flat bases, clean noses, good manners, and winning personalities. Applied to an entire batch of bullets, and in turn, several batches of bullets from the same mold and alloy in comparison with each other, the scale is able to tell you how consistent you are on a very basic level. The scale doesn’t care what the defect is, it will see it. It may miss a bullet because that bullet is so jacked up that it has contradictory flaws that fool the scale, but the chances of that bullet previously making it out of the mold unnoticed by you for any defect of appearance,( and also being the only one in the whole batch) is almost impossible. Observing proper casting technique as taught on this forum takes care of 98% of the inconsistencies you have in your process just by observing and following a process that applies to all molds equally. But, this process is specific to each mold you have and while some of your technique will apply to different molds equally, you can be sure that each mold will have a personality of its own, and this technique will dial you into it very quickly.
The way you use bell curves to teach you is to use them to dial in each of the steps listed above that have an effect on bullet mass or physical fitness. (don’t worry, you’ll be taking the good ones and shooting them as you go along. This is a long term project that will take many casting sessions to perfect.)
What you do is use your normal method to cast 100 bullets (I personally find this to be a minimum for any sort of a telling bell curve) and line them up based on bullet weight with each row representing .1gr increment of your proficiency.
Do not cull any bullets as you do this. This is the time for truth and brutal honesty, not looking good on paper. It’s not a measure of you it’s a measure of your technique.
Once you have all your bullets lined up, take a picture of the result, or use a pencil to outline the shape of the bullets on the paper and record what your spread was.
At this point, you may look at the brutal honesty of the bell curve before you, and postulate an opinion about why it’s bigger than you thought it would be (and I can almost guarantee it’s not going to be as perfect as your thought). You say “oh well, that was because I waited too long between fills. It’s just not my best run is all.”
Go back to your pot and cast another 100 bullets having corrected what you thought was wrong. Plot them again and see if you were right. (Remember: Brutal honesty. No matter how badly you want to scrape the corners off the base of the Christmas tree, you must not, or you are only fooling yourself. Those defects are trying to tell you something!)
After you have tried what you said, and it really didn’t make the change you thought it would, you’re going to get frustrated. May I suggest you try going right down the list above and choose to explore each variable? It’s time consuming, but I found it to be very fun, and each bell curve teaches you things, and there will be many “light bulb moments”.
Lets just walk through the casting principles I listed above and I’ll show you how to measure a few of them. There is a lot to learn and it’s the coolest thing in the world to find things you thought were your problem were not, and other things you thought didn't matter actually do!
1.Alloy temperature. Change your pot temperature 25 degrees at a time and plot bell curves. Keep the best one.
2.Prime the spout of the pot. If you don’t, I would challenge you to do so and observe the change in your spreads. I went as far as to witness each cavity of my mold and separate the good bullets (+- .2 grains) by cavity they dropped from. Turns out, cavities 1 and 2 were always lighter than cavities 3 and four because cooler alloy is thicker than hot alloy, and that was how much lead it took to stop the nozzle from changing the alloy temperature. Once I started priming the spout for a whole second, the variation between cavities disappeared.
3.Stream location in the sprue hole. This is cool. If you do not take care to hit the sprue hole consistently, then do so, and see the difference. If you throw the lead straight down the hole, then do it every time, or clip the edge of the hole a certain amount, and do it every time. Plot a curve, try something else, and plot again. You’ll be surprised such a little thing makes such a difference in your brutally honest bell curve.
4.Puddle size. Try different size puddles and observe the difference.
5.Puddle freeze time. This is a big one that will show a difference. Try running hot enough for a 3 second freeze, and try running hot enough for a 5 second freeze, and observe the result in the bell curve.
6.Dwell time. After dumping the bullets, we wait a certain amount of time. But it’s just a wild flying guess how much based on what happens several steps later. I suspect that most of the time, we end up running just a little proud or a little shy of where the mold wants with that alloy at that temperature. We go back in just a little too soon, and see the puddle takes longer to freeze, so we wait a little bit longer than usual on the flip side, and hope it works etc etc etc. Well, the bell curve sees that variance when you plot. The fact that you were not dwelling the correct amount of time means that you’re always going to be chasing rainbows unless you test what the correct dwell time is and stick to it like glue. If you fill too soon, then dump the batch and quit doing that!
This is very simple, use bell curve comparison to dial in your process to perfection. This is just like going to the eye doctor and he has you compare prescriptions with his expensive machine. He doesn't choose your prescription you do. He depends on your brutally honest comparison of “better or worse” to quickly find your prescription out of about 1000 options. Because each test gets you better and better, the final result represents the limit of what the available technology can give you. That’s exactly what I’m proposing here. Each mold has a “prescription” that will make it focus your effort better and you just need to run a few tests to determine what it is.
What if your eye doctor ran his business like we usually cast our bullets? I think it would be something like this:
You walk in and tell him you need a pair of glasses because you can’t focus.
He tosses a used pair of glasses across the counter and says, “these here worked for me when I was your age. That’ll be $150.99.”
You try them on and inform him that they’re better, but not really as good as you had hoped.
He says, “Don’t be silly! You have to wear them for at least 6 months before you can tell whether they work or not!”
That’s about how it is with cast boolits. The first thing you have to do is learn to see and that involves following the steps provided, but after you learn to see you must learn to focus. And focus is not a one size fits all proposition. It’s a very personal thing that you must learn for yourself and about yourself in order to be effective. It’s easy to paint with a broad brush and say that everybody does the same thing, but when you get down to the details, you find that casting good bullets is as personal a thing as a pair of shoes, or glasses. Each person does it slightly different.
I teach people to cast very often here at the shop (if you want to swing by, Sunday is casting day and I don’t charge a thing.) and I have learned not to bust on people when they do something different than I do. As long as it works for them, its fair play, and I love seeing the diversity of style (sometimes I even learn something myself! LOL!) I encourage people to develop their own style, but not at the expense of precision and consistency.
Now, one thing I would like to say about this is that if you want absolute perfection, you are going to have to run back through and retest each variable I mentioned (and any that you change) the reason being that these things are all connected, and when you change one, you change the others slightly too. However, if you keep whipping your process with bell curves, you will get more and more consistent and more and more focused till you can cast with proficiency that is absolutely astounding. (My personal goal is 299 good one out of a 300 bullet session.) I have been doing this for a year now, and it’s getting better all the time.
This was my last run:
340 bullets cast. 299 good ones that weigh 0.0 on a tarred digital scale, and 41 bad that weigh anything but 0.0 and only one that was lighter than 1gr. I’m going back over my process each time I cast and looking to improve myself.
This is a progression of my improvement so you can see how this has worked for me, ending with the example I just gave. Some of these curves are not 100 each, and some are more than. The determination that 100 minimum is a recent conclusion of mine.
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BTW, you find a light bullet, its probably a void:
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Again, what you see in the orange tote is 299 bullets that weigh 0.0 on a tared scale. All those on the paper towel are the ones that did not weigh 0.0 and would be clustered around the bottom of a looooooong line of good ones if I plotted them into a bell curve. That's the best I have don'e so far.
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Like I always say, it’s not the only way, but it’s a way that might work for you. Feel free to try it and use it to improve yourself.
Thank you.