optimum temperature for casting bullets?

[10x]

Once upon a time the forest land of northern Canada was laced with small sawmills, usually powered by a steam engine.
Everyone of these little mills required pouring babbit bearings from time to time. The babbit material was nearly identical to the lead alloys we pour bullets with.
The operators of these outfits soon learned how to get the metal at the right temperature and they all used the same method of judging temperature.
They cut a sliver from a dry, seasoned piece of pine. They pushed this sliver of wood into the hot metal and counted to three, then took it out. The color of the sliver when it came out should be about the color of the crust on fresh baked bread.
That was the ideal temperature for pouring bearings, or for making lead bullets.

Babbit for bearings is a much different alloy than lyman #2.
Real babbit for bearing is usually 86% tin, 7% copper, 7% antimony or a close approximation there of.
My grandfather and father could pour babbit bearings and they had a stock of babbit alloy. It made bullets that would ring.
I would add 1/4 oz of babbit alloy to my wheel weight alloy in the late 1960s to make my 30-30 bullets harder.

 

[Canuck44]

Lets not over think this. I have manage 1/2" groups out of my Husqvarna 30-06 at 100 yards off a rest with water quenched WW cast as hot as the RCBS melter will produce using a 311291 boolit and recetly a 1 3/4" group out of my scoped #4 Lonbranch using the same method.

I use a small computer fan blowing over my three molds when I cast. This seems to keep the molds at the right temperature as I see few frosted boolits. You can buy the fans at Canadian Tire for next to nothing.

I put a 20# Lee Pot over top of my RCBS 20# (I had an old 10# Lee before). I pre-melt my ingots and when the RCBS drops to about half full I refill from the Lee. All my sprue goes back into the Lee and I add WW ingots as required. I use sawdust to clean my melt. Some use candle wax but it will effect the tin in your ally - sawdust works mo betta as my late friend Felix Robbins used to say. I use Felix Lube and a soft commercial lube for all my shooting.

I water quench all my rifle boolits and 9MM and 40 Cal pistol boolits and those I intend for the .357Mag/44mag or rifle pistol carbines. All other boolits get air cooled.

Not very scientific but the method produce repeatable results that shoot as well as my eyes and equipment allows.

To the OP as another suggested try shooting them as cast. The gun will round out any of the out of round boolits quickly and you might be surprised at the results. The old Enfields aren't tack drivers but it is fun to max out the rifle's accuracy. The scope on mine did wonders for my groups. Younger eyes and a better original sight would have too, but neither of those are options.:>)

Bob

 

[10x]

Lets not over think this. I have manage 1/2" groups out of my Husqvarna 30-06 at 100 yards off a rest with water quenched WW cast as hot as the RCBS melter will produce using a 311291 boolit and recetly a 1 3/4" group out of my scoped #4 Lonbranch using the same method.

I use a small computer fan blowing over my three molds when I cast. This seems to keep the molds at the right temperature as I see few frosted boolits. You can buy the fans at Canadian Tire for next to nothing.

I put a 20# Lee Pot over top of my RCBS 20# (I had an old 10# Lee before). I pre-melt my ingots and when the RCBS drops to about half full I refill from the Lee. All my sprue goes back into the Lee and I add WW ingots as required. I use sawdust to clean my melt. Some use candle wax but it will effect the tin in your ally - sawdust works mo betta as my late friend Felix Robbins used to say. I use Felix Lube and a soft commercial lube for all my shooting.

I water quench all my rifle boolits and 9MM and 40 Cal pistol boolits and those I intend for the .357Mag/44mag or rifle pistol carbines. All other boolits get air cooled.

Not very scientific but the method produce repeatable results that shoot as well as my eyes and equipment allows.

To the OP as another suggested try shooting them as cast. The gun will round out any of the out of round boolits quickly and you might be surprised at the results. The old Enfields aren't tack drivers but it is fun to max out the rifle's accuracy. The scope on mine did wonders for my groups. Younger eyes and a better original sight would have too, but neither of those are options.:>)

Bob

It is interesting how you solved the problem with the Lee bottom pour drip o matic pot.

I have found that temperature control of the alloy to within a few degrees reduces just one of the factors that gives wrinkled bullets.
I have also discovered that different molds like different alloy temperatures.
And that different alloys (pure lead, wheel weights, and linotype) have an alloy temperature (all different) that they start to give good cast bullets.

A casting session goes way quicker with a clean pre heated mold and the lead up to the casting temperature you know gives a good bullet. If you have a problem then it is either the alloy mix or oil in the mold.

I have found that the lee pots have to be run a little hotter because the diameter of the pour allows the lead to cool between spout and mold - this can give a wrinkled bullet - up the temperature of the pot 5 or 10 degrees and the wrinkles go away.

Every variable you can eliminate gives you the chance to cast a better, more accurate, bullet. Temperature is one of those variables.

 

[Canuck44]

It is interesting how you solved the problem with the Lee bottom pour drip o matic pot.

I have found that temperature control of the alloy to within a few degrees reduces just one of the factors that gives wrinkled bullets.
I have also discovered that different molds like different alloy temperatures.
And that different alloys (pure lead, wheel weights, and linotype) have an alloy temperature (all different) that they start to give good cast bullets.

A casting session goes way quicker with a clean pre heated mold and the lead up to the casting temperature you know gives a good bullet. If you have a problem then it is either the alloy mix or oil in the mold.

I have found that the lee pots have to be run a little hotter because the diameter of the pour allows the lead to cool between spout and mold - this can give a wrinkled bullet - up the temperature of the pot 5 or 10 degrees and the wrinkles go away.

Every variable you can eliminate gives you the chance to cast a better, more accurate, bullet. Temperature is one of those variables.

The 20# Lee drips but so does the RCBS, although not as much. When I cast I want to cast and waiting for the light to go out on my RCBS is just a waste of time so pouring the Lead from the Lee just made so much sense.

With the RCBS pot set on the max heat my boolits come out fully formed and + or - one grain from my molds. For my rifles I used to sort them but for what I am capable of with the rifles I use, #4, a Swiss and a Marlin 30-30 now along with three pistol caliber carbines the method works for me. If I was younger and had the personality trait to deal with the fine tuning you suggest I would be into it but frankly I have not. I do respect those who are though and wish them well.

For handgun use it is a whole different ball game and given the variables involved casting temperatures would be vary low on the list of my concerns. If the boolits are fully formed and hard or soft enough for the caliber then I doubt slight variations in boolit weight make much difference in the final result for IDPA/IPSC or PPC shooters,

To the OP you really have to decide what you want to achieve with your boolits. Are you hunting out to 100 yards or planning to do long range military and bullseye shooting or just 50 yard plinking and you want your bullets to go where you think you are aiming at targets of opportunity (cans, milk jugs, and rocks).

From my experience if you cast from clean molds at as high a temperature as our hobby equipment will allow, once the mold gets to operating temperature your boolits will be as good as you can cast with the alloy you are using. While a few degrees one way or another may be a variable I haven't noticed it in the type of shooting I do but then I don't track alloy temperature and shooting results so it is fair to say I don't know if temperature variations have any affect. I did find out early that to cool a melt produced poorly formed bollits. If you get wrinkled boolits when your molds have been heated cast hotter. Someone has posted what he believe is the ideal temperature for one or all of his molds use it and see how you make out,

I get to where I want to go and you have to decide what you want to go.

Take Care

Bob

 

[10x]

The 20# Lee drips but so does the RCBS, although not as much. When I cast I want to cast and waiting for the light to go out on my RCBS is just a waste of time so pouring the Lead from the Lee just made so much sense.

With the RCBS pot set on the max heat my boolits come out fully formed and + or - one grain from my molds. For my rifles I used to sort them but for what I am capable of with the rifles I use, #4, a Swiss and a Marlin 30-30 now along with three pistol caliber carbines the method works for me. If I was younger and had the personality trait to deal with the fine tuning you suggest I would be into it but frankly I have not. I do respect those who are though and wish them well.

For handgun use it is a whole different ball game and given the variables involved casting temperatures would be vary low on the list of my concerns. If the boolits are fully formed and hard or soft enough for the caliber then I doubt slight variations in boolit weight make much difference in the final result for IDPA/IPSC or PPC shooters,

To the OP you really have to decide what you want to achieve with your boolits. Are you hunting out to 100 yards or planning to do long range military and bullseye shooting or just 50 yard plinking and you want your bullets to go where you think you are aiming at targets of opportunity (cans, milk jugs, and rocks).

From my experience if you cast from clean molds at as high a temperature as our hobby equipment will allow, once the mold gets to operating temperature your boolits will be as good as you can cast with the alloy you are using. While a few degrees one way or another may be a variable I haven't noticed it in the type of shooting I do but then I don't track alloy temperature and shooting results so it is fair to say I don't know if temperature variations have any affect. I did find out early that to cool a melt produced poorly formed bollits. If you get wrinkled boolits when your molds have been heated cast hotter. Someone has posted what he believe is the ideal temperature for one or all of his molds use it and see how you make out,

I get to where I want to go and you have to decide what you want to go.

Take Care

Bob

Casting is a bit of an art. You are spot on with the clean molds.
And casting hot will work well - I use a PID to a) read the temperature so that I know it is hot, and b) keep the temperature above the point where I start to get wrinkles.

Now that I have the ability to read the temperature of the alloy and with pre heating molds on a hotplate I can get good bullets on the first or second casting cycle. It is a great feeling to run through 10 lb of lead with a 6 cavity mold and crank out between 300 and 500 bullets with no faults.

I cast 45 grain and 55 grain 22 caliber bullets and keeping over a minimum temperature seems to be critical in getting bullets that look to be flawless. (Adding a little tin helps too)

 

[Canuck44]

Some witch craft in there too.

Bob

 

[jethunter]

The perfect temperature is when you can mold perfect bullets and there is no single perfect temperature for all conditions.

For instance: You can run the pot cooler if you cast faster. You probably need to run a bit warmer pot temperature in the winter when the mold cools off faster. Smaller bullets impart less heat to the mold and need hotter pot than a larger bullet to maintain mold temperature.

You adjust casting speed and pot temperature to get the right mold temperature.

Generally speaking, the pot temperature needs to be at least 650F, and probably doesn't need to be run much over 750F in most cases although i do have a couple molds that need more than that and one that does best at under 650F. Start at 700F and adjust from there. You'll find that you can drop the pot temperature a bit once your mold warms up. If you are having trouble getting good fill - then turn up the heat. If fill is good but it's taking too long to harden - then turn down the pot. Let the mold and the bullets tell you whan the pot temperature is right.

 

[10x]

The perfect temperature is when you can mold perfect bullets and there is no single perfect temperature for all conditions.

For instance: You can run the pot cooler if you cast faster. You probably need to run a bit warmer pot temperature in the winter when the mold cools off faster. Smaller bullets impart less heat to the mold and need hotter pot than a larger bullet to maintain mold temperature.

You adjust casting speed and pot temperature to get the right mold temperature.

Generally speaking, the pot temperature needs to be at least 650F, and probably doesn't need to be run much over 750F in most cases although i do have a couple molds that need more than that and one that does best at under 650F. Start at 700F and adjust from there. You'll find that you can drop the pot temperature a bit once your mold warms up. If you are having trouble getting good fill - then turn up the heat. If fill is good but it's taking too long to harden - then turn down the pot. Let the mold and the bullets tell you whan the pot temperature is right.

Spot on!
The advantage of the PID is that it gives you an accurate reading of the current pot temperature. My Lyman lead thermometer reads some 60 degrees higher than the Thermocouple.
One of the disadvantages of the Lee thermostat is that it lags considerably and gives a wide range of alloy temperatures.
Last night I cast 250 55 grain 0.224" bullets - the NOE mold likes a minimum temperature of 680F - set the PID at that temperature, preheated the clean mold, and got bullets without wrinkles on the third cycle of casting (5 cavity mold).

I can drop alloy temperature to 330 C (625 F) when casting 200 grain 44 caliber bullets - although warmer works too. At 360C the larger mold will get warm and start to give frosted bullets.

 

[sawzall]

The perfect temperature is when you can mold perfect bullets and there is no single perfect temperature for all conditions.

For instance: You can run the pot cooler if you cast faster. You probably need to run a bit warmer pot temperature in the winter when the mold cools off faster. Smaller bullets impart less heat to the mold and need hotter pot than a larger bullet to maintain mold temperature.

You adjust casting speed and pot temperature to get the right mold temperature.

Generally speaking, the pot temperature needs to be at least 650F, and probably doesn't need to be run much over 750F in most cases although i do have a couple molds that need more than that and one that does best at under 650F. Start at 700F and adjust from there. You'll find that you can drop the pot temperature a bit once your mold warms up. If you are having trouble getting good fill - then turn up the heat. If fill is good but it's taking too long to harden - then turn down the pot. Let the mold and the bullets tell you whan the pot temperature is right.

Best post on this thread! It's all about mold temperature. You can pour 900F alloy in a cool mold and have wrinkled boolits or 650F alloy in a mold running too hot and have frosted boolits. Everyone's techniques and rhythms are different so with the same exact mold, what temperature works for me may not work for you!