What Temps do you cast your varieties of bullets at?

[blasternank]

I've been reading a great deal on this forum. Great info! Everyone says you need consistency to get the best casts. I've seen people say that for big boolits less temperature is best and for small boolits it's best to be hotter. I've also seen people say never heat your lead up more than 750 degrees and others say they go hotter than that. My question is simple.

What temperature do you use to cast your various bullets?

Right now I'm going to cast a .510" bullet plus 9mm, 38/357, 45 acp and probably 44 mag. But I would like to see what you use for a variety of bullets as in the future I may be casting for them as well. If you have a reason why you use a certain temperate or pro's or cons of certain temps with certain rifle/pistol casts I'd love to hear about them.

Thanks.

[454PB]

There are too may variables to give you a solid answer. The alloy, boolit size and weight, mould design (steel, aluminum, brass) and number of cavities are just some of the factors involved.

That said, I tend to cast hotter than most members on this forum. 650 degrees is about minimum and 750 is where I usually end up. I didn't even have a lead thermometer until about 3 years ago, and adjusted temperature by the resulting boolits. To me, the end result is more important than a reading on the thermometer.

[peerlesscowboy]

The rheostat stuck and the plastic knob broke on my ol' Lyman 10 lb bottom pour many years ago so I pretty much just run the same heat for everything. I sometimes adjust the valve for slower/faster and fine tune by the appearance of the bullets Kind'a crude I guess but hey........it's more sophisticated than sitting out over the campfire at night casting bullets for the next days buffalo hunt?

John C. Saubak

[geargnasher]

Like 454 said, there is no way to give you an accurate answer that will work for you in every situation.

I notice that you do not specify WHICH temperature. That may be because you don't know that there are three temperature variables in casting, and they are all crucial to getting good results. Here's the way I see it:

ALLOY TEMPERATURE/POT TEMPERATURE: This is the one that everyone fights and argues about, because there is so little understanding of metallurgy among most boolit casters, and other factors that I'll get into in a minute cloud the issue of pot temp and make folks come to the wrong conclusions.

One of the great enemies of the boolit caster is oxidation. Oxide scum, or "dross", forms on top of molten boolit metal anywhere it is exposed to oxygen, like at the surface of the pot and on the surface of the stream as it's being poured into a mould. To protect against the flash oxidation of lead and antimony, tin is added in small quantity to create a moving oxide barrier on the melt's surface, thus allowing it to flow better and fill out our moulds. The issue with temperature arises because the oxidation rate of tin accelerates rapidly with rise in temp from anything above fully molten. A typical boolit casting alloy contains mostly lead, a few percent antimony and one or two percent tin, unless using a "type" metal alloy, Lyman #2 or such. These types of alloys are molten, or at full liquidus, at anywhere from 475F to 600F depending on composition. For most casting purposes, I've found that anywhere from 75 to 125 degrees above full liquidus is all that's needed, or wanted, for casting. Take, for example, typical clip-on wheel weight alloy with one percent tin added. This will melt at about 560-570F, and starts to cast really well at about 650. I watch the melt temp and usually run it to about 675F or so during the casting sesson. OK, heres why: At temperatures approaching 750F with this type of alloy, the tin begins to oxidize at an astronomical rate, creating a thick dross layer and gradually depleting the tin from the alloy. Antimony oxidizes out, also. This is not gravity segregation, it's oxide segregation because tin and antimony oxidize at a different rate from lead. Overheated alloys also have issues filling the moulds because the tin oxide protective surface film on the poured stream is rendered ineffective by the higher temperatures, and the total tin content of the alloy is getting less and less as the tin forms oxides at the top of the pot. Once the tin is oxidized out, the alloy still won't cast as well at reduced temperatures unless the tin oxides are chemically "reduced" back into the melt using hyrocarbon sarificial recucants (candle wax, sawdust, etc.) The higher the tin percentage, the lower the melt point of the alloy (to a point) and the lower the pot temperature needs to be. I feel it is important to recognize that, in principle, alloy temperatures should be maintained in the casting pot at a point that is best for the alloy composition you're using. Usually that's 650-725 for most WW material, Hardball, and Taracorp Magnum, a little lower for Lyman #2 and lower still for pure Linotype, 20:1, 16:1 and such. For 40:1, pure lead, or very mild alloys around bhn 6-8, a higher pot temperature is desired to get good mould fillout, and oxidation of tin, since there isn't much present, is much less of a concern. These low-tin alloys can be run over 900F with no ill effects if that is what the mould design needs to fill out.

MOULD TEMPERATURE: This is where many peope get confused. They shouldn't, it's simple. Your mould blocks need to be a certain temperature in order to cast good boolits with nice, sharp edges, full fillout, square, clean bases, and consistent weight. The temperature a given mould likes varies on mass, block material type (coefficent of heat varies greatly between types of brass, aluminum, steel, and iron alloys), cavity mass/block mass proportion, ambient temperature, and boolit design. The important thing to remember is that mould temperature is king. Too many focus on pot temperature when they should be focusing on the mould, since the mould is what affects the initial flow and cooling rate of the alloy in boolit form. Most newbies don't realize how important a hot mould is, and will make one pour every minute or two and wonder why they can't get rid of the wrinkles in their boolits. Often it takes a good preheat of the moulds and 20 or more pours to get the blocks and sprue plate up to a good casting temperature, and then two to four pours per minute to maintain that temperature once it's reached.

Here are some temperatures that work for me, I present this as an example, your and other's milage will vary considerably based on your unique circumstances and appearance preference for boolits: Lyman two cavity mould, light boolit: about 325-350F, large cavity, heavy boolit, the same, but much slower casting pace to keep same temp. Lee two cavity moulds seem to like anywhere from 350 to 425F depending on boolit design, I have the best luck running them as hot as possible, meaning I cast as fast as I comfortably can with an alloy only about 75F over liquidus and never overheat the mould. Brass blocks seem to like a slightly hotter alloy in addition to casting fast for slightly frosted boolits (with WW alloy), I usually run these at about 380-400 with alloy about 100-125F over liquidus, this is because brass loses heat so fast you have to really keep pumping it into the blocks to keep them up to temperature, and a slightly hotter pot will help. Now, there's a good point that I mentioned I'd explain above: Many casters try to compensate for a mold that's too cool by cranking up the alloy temperature, and when that overheated alloy finally imparts enough heat to the mould to make decent boolits at their snail's pace of casting, they wrongly conclude that they must run their wheel weight alloy at 800-900F to get good boolits. What the should have done, but often don't know to do due to all the misinformation running rampant, is cast faster to get the mould hotter with the alloy still cool enough to be happy sitting in the pot for hours without burning out all the valuble tin. I've caught a lot of flak here and elsewhere for continually repeating these facts of alloy vs. mould temperature, but the physical propeties of metals are what they are, not something I make up. If you don't believe me, go reference the casting section in Lyman Cast Bullet Manual #3, as well as any edition of The Metals Handbook, it's all in there, and if you follow this you'll find I'm not wrong.

AMBIENT AIR TEMPERATURE: This one, along with humidity, affects our boolit quality considerably as well as alloy and mould temperature. Each Winter I see various "cold weather" casting techniques posted, and certain measures have to be taken to still get good boolits in a zero-humidity, freezing atmosphere. Same goes for casting in 90% humidity in an evaporating atmosphere near sea level on a 100 degree day. This is where each caster has to put it all together, experiement, and learn what works best for them on any given day. The important thing for every caster is to have a basic understanding of the variables with which they are dealing, how each affects the other, and how to sort it all out quickly and maintain consistency through a long casting session.

Hope this helps,

Gear

[Walter Laich]

I cast all of mine around 725*

Right now I'm pretty much only casting .45 Colt and .45-70 bullets

[gray wolf]

I have to agree, it's a hard question if you want a fine tuned answer.
Like asking whats a good load for my rifle.
Whats right for you depends on,
your metal, your casting speed, mold size, and a few other things. Like has been said, we can get a person started but the fine tuning comes from the person doing the casting,and knowing what to look for. Some learning needs to be done, tricky at first ---but not impossible.

[Charlie Two Tracks]

I am by no means an experienced caster but I have found out that it is the mold temperature and not so much the lead temperature that makes a difference. I keep my lead at 700 degrees most always. The boolits can vary in size by how hot or cold it is. That's what seems to be working for me now.

edit: dang! you guys got all that out while I was typing this. I have to get better at typing!

[XWrench3]

everything i cast is run at 750 defrees, plus or mius as little as i can get it. if it gets over 800, i either stop and let it cool off, or add more metal. 50 degrees below that, and things just done fill out well.

[FAsmus]

Gentlemen;

I've never used a alloy thermometer for the 30-some years I've been casting bullets.

There are enough variables to contend with that concentration on any one factor isn't going to do you much good.

I find myself running alloy very hot at times to improve its flow - hot enough that the top of the melt turns black as the slag oxidizes. At other times I run cool enough that the pot pretty much needs little or no attention besides clearing an area to dip the ladle each pass until it runs empty.

Different molds will at times be quite challenging to work with - patience is the only way to work these things out - pressure feeding the cavity, Wosika swirl from 1/2 inch above the fill-hole, various bottom-dump pots lend their own problems and solutions.

All-in-all I prefer to cast at around 40 degrees. This is cool enough that my furnace does not overheat me and warm enough that me feet don't get cold.

Good afternoon,
Forrest

[357shooter]

For soft alloy in 38/357, hot works well. I normally cast with 98% lead and 2% solder, with 150 - 200 grain moulds, they like 900 - 975 degrees.

The mould temp is pretty important too, just posted some test results & graphs in another thread. Again, with the soft alloy and with a 168 grain bullet (358-429) it likes the mould hot at (measure in the mould block w/the NOE thermometer) 530 degrees. That's 450 in the cavity when heated on a hot-plate or dipping it into the alloy.

Wheel weights take less heat, harder alloys work well with even less heat.

[44man]

All of my harder alloys from WW's up, I just set the Lee pot at 750. For soft I go to 800 or just above. I don't use a thermometer unless I am making an alloy in my smelting pot.
Boolits are controlled from casting tempo and too many years of experience to admit from this old guy! I don't even need to pay any attention and if you watched me with my slow and easy casting, you would just go home shaking your head. It makes no difference between a 100 gr or a 560 gr boolit, all gets automatic with experience.
Most casting problems are caused by frantic, need to rush thinking. Preparation and mold temp is first, then when you can dump a 20# pot without a single reject, you are there.
Leave the dial alone, you are the control!

[songdog53]

I try to cast between 700 and 800 because i have found i get frosty boolits quick after getting over that temp. Course mold heat has to be figured into that but I think is something is no set rule on, because each one uses different mixtures of lead and different molds. I found i had to fine my own sweet spot and remember which boolits likes. I poured a bunch of 44 caliber that weighs 255 and their sweet spot was like 725 but 225gr 45's like it wee bit hotter and have to watch or mold heat.

[white eagle]

what Jim said

[357shooter]

Who's Jim?

[dragonrider]

I cast with only straight WW's at 800 to 850. Fillout is normaly good, on those occaisions when it isn's I find I am casting too slow or spending too much time on the wet rag.

[rintinglen]

I run with Gear on this one. It can hardly be said better. His metallurgy explanation ought to be a sticky some where.
There is one other element that comes into play and that is the temperature control element on your pot. My old 10 lb lee would cycle nearly ,20 degrees, by itself. Your metal casting temperature should be high enough so that the low point doesn't get you in trouble.
However, I find that for me, I have to run hotter--700-750--with non-ferrous molds to get good boolits, and when I'm casting big boolits for my 45-70 from iron or steel, The dial goes way down. I have a four cavity 457-192 that goes from cold wrinkled to good in about four casts, and then gets so hot in four more casts that the sprue takes 30 seconds to fully freeze. The temperature has to go way down for that one to make good boolits. At least, to make them at an reasonably fast rate. On the other hand, I recently bought an NEI aluminum 4 banger 32-100 that I can't cast fast enough to get good boolits out of it. Aluminum and copper are extremely good conductors and don't hold the heat as well as an iron mold will. Often times with a mid to light weight lee 6 banger, the first four boolits drop perfectly, but the last one or two show wrinkles because the mold has cooled enough at the end to freeze the metal before you get good fiil out.
There is a lot of science involved in boolit casting, if you care to make it so, but I cast half a ton of 38 wadcutters back when I didn't know squat, and can only wish that I could still shoot as well as I did back in the disco days--sigh.

[44man]

I run with Gear on this one. It can hardly be said better. His metallurgy explanation ought to be a sticky some where.
There is one other element that comes into play and that is the temperature control element on your pot. My old 10 lb lee would cycle nearly ,20 degrees, by itself. Your metal casting temperature should be high enough so that the low point doesn't get you in trouble.
However, I find that for me, I have to run hotter--700-750--with non-ferrous molds to get good boolits, and when I'm casting big boolits for my 45-70 from iron or steel, The dial goes way down. I have a four cavity 457-192 that goes from cold wrinkled to good in about four casts, and then gets so hot in four more casts that the sprue takes 30 seconds to fully freeze. The temperature has to go way down for that one to make good boolits. At least, to make them at an reasonably fast rate. On the other hand, I recently bought an NEI aluminum 4 banger 32-100 that I can't cast fast enough to get good boolits out of it. Aluminum and copper are extremely good conductors and don't hold the heat as well as an iron mold will. Often times with a mid to light weight lee 6 banger, the first four boolits drop perfectly, but the last one or two show wrinkles because the mold has cooled enough at the end to freeze the metal before you get good fiil out.
There is a lot of science involved in boolit casting, if you care to make it so, but I cast half a ton of 38 wadcutters back when I didn't know squat, and can only wish that I could still shoot as well as I did back in the disco days--sigh.

This is NOT how casting should go. Nothing should ever change at any time.
The biggest problem is PRODUCTION and some of you would try a 20 cavity mold. We are not foundry owners, we have simple tools.

[white eagle]

Who's Jim?

[geargnasher]

I try to cast between 700 and 800 because i have found i get frosty boolits quick after getting over that temp. Course mold heat has to be figured into that but I think is something is no set rule on, because each one uses different mixtures of lead and different molds. I found i had to fine my own sweet spot and remember which boolits likes. I poured a bunch of 44 caliber that weighs 255 and their sweet spot was like 725 but 225gr 45's like it wee bit hotter and have to watch or mold heat.

Frosty boolits are a function of MOULD TEMPERATURE, not alloy temperature.

I can show you how to cast boolits that look like a hot-dipped galvanized nail from wheel weight alloy at 625F, and I can also show you how to cast shiny boolits with 850F alloy.

The difference is how hot the mould blocks are. This factor IS a "set rule" universal among antimonial alloys, it is not a unique function of an individual mould. Regardless of alloy temp, whether the boolits are frosty or not depends on how hot the mold is, period.

Gear

[HammerMTB]

Most of my casting is at 725F, using WW or some WW with an adder that benefits my purpose for the boolit.
I find it somewhat easier to bump up to 750F or slightly higher if I am casting pure Pb, which isn't often. Most of that is due to mold temp, and wanting a hotter melt to carry more heat into the mold.
One day I may have to find out what it will take to pour zinc boolits, or maybe we should rename them zoolits.