Does heat affect size of bullets?

[spurrit]

I'm just getting into casting bullets, and have noticed that some are undersized and will pretty much fall through the sizer die, while some are oversized to the point that it takes some effort to push them through, using my Lee hand press. Since they all come from the same batch of lead, the only variables I can think of would have to do with heat~the temperature of the mold and the temperature of the pot. Is a variation in temperature to blame for the variation in size?

Right now, I'm using a cast iron pan over a turkey fryer. I don't have a lead thermometer yet. I'm dropping the bullets directly from the mold to a bucket of water. Any help from the BTDT crowd appreciated!

Now, I'm off to :Fire: ! ! !

[montana_charlie]

If you are just getting started, you may not be squeezing on the mould handles the same amount each time you fill the mould. A 'light' grip can result in fatter bullets.

You didn't say, but I'm assuming all bullets came out of a single cavity mould. If there is more than one cavity...that may be the answer.
CM

[Baron von Trollwhack]

I think casting temperature does affect cast bullet size. Easy for you to test your own efforts. Start casting as normal and put your bullets in a line and measure them when cool. Of course you already know mold/lead temperature affacts how well the bullita fall out of the mould. BvT

[44man]

It indeed does. A cool mold and lead will give smaller boolits. Within the right range of temperature, the mold will expand more and cast larger boolits. Then after the mold is as large as it can expand and the lead gets too hot, boolits will shrink more and cast small again.
Once everything is right for the alloy, a steady rhythm has to be maintained.

[spurrit]

44, do you know of an optimum temperature that works for you? Also, how, in your experience, does temperature effect the weight?

Right now, I'm mostly using 6 cavity molds, so I can make a bunch of bullets for cowboy shoots in a reasonable amount of time.

I have some single and double cavity molds for my "good" bullets for hunting and such.

For cowboy shooting, you don't exactly need to be precise. If the targets were any bigger and closer, I could pee them down during a stiff crosswind.

[xr650]

You might try to cast some without quenching them.
Lay them on a rag so you can look at them in order of cast.
I am still new at this. I will start casting and think I am doing good.
As my mould gets to temp I see my first ones were not filled out like I thought.

I have also proved to myself that way too hot will cause shrunken drive bands. I can't describe it but they look different than a cold mould boolit.

I haven't quenched/heat treated any boolits yet. I have shot several hundred of my own air cooled and no leading.

Good luck.

I don't savvy the BTDT crowd, but I'm sure I'm not one.

[spurrit]

BTDT=Been There, Done That!

[spurrit]

Props to Maven for voting, "dunno". It's nice to see someone on the internet that's willing to admit it!

[xr650]

Thanks for the clarification.
I think I'm part of the BTSTU (been there, screwed that up) crowd.

[spurrit]

Yeah, I'm trying to restore a barreled action I found in the buggy shed when I was a kid. I tried to "fix" it, with predictable results.

I might just mount it on a board as a monument to not working on something over your skill level, and using the right tool for the job.

I might also scrounge up some pocket watches I tried to "fix" as a kid.

As an adult, with all these broken momentos, I honestly don't see how Dad kept from killing me. It musta been damned tempting. I never realised what a merciful saint he really was, until I started buying and having to replace my own stuff!

[44man]

I usually cast my revolver boolits around 750* and the large BPRC boolits at 800* or so. Just depends on if the boolits are filling good but I back down from frosted boolits as they can be too small. A lot depends on mold size too with my larger ones retaining more heat.
I pre heat molds to 500* while the lead is coming up to temp and the first boolit will be perfect.
I water drop because I need hard boolits with the neck tension I use. They take a while to fully harden but I have good luck after a week. Two is better.
Boolits with antimony also grow as they age with smaller calibers growing less. My .476" boolits age to .478". They chamber and shoot great so I don't size them again. I use a .476" Lee die to remove excess lube that I apply by hand and do it soon after casting, then I let them grow and harden.
I do have a 45-70 boolit for my BFR that will not chamber when it gets larger and I didn't have time to size them right away so now I have to after they are aged. Doesn't seem to hurt anything.
The problem with using flame to cast is continual heat change. A small breeze can change everything back and forth. Those that do it a lot use a shroud around the flame.
I don't think the process can be explained for every condition and mold, it is mostly experience and altering things until you get what you want.
It's funny but the pot that gives me the least trouble is a cheap Lee 20#. I use a ladle.
My old Lyman would cycle too slow to the point lead started to freeze in the pot. I removed the thermostat and used an adjusable voltage control. It worked for years until the control burned up. The price of the control is now so high, a new pot is cheaper.
If I had the smarts I would design an electronic voltage control that would not burn up. Then any pot could be held to a few degrees.

[warf73]

It indeed does. A cool mold and lead will give smaller boolits. Within the right range of temperature, the mold will expand more and cast larger boolits. Then after the mold is as large as it can expand and the lead gets too hot, boolits will shrink more and cast small again.
Once everything is right for the alloy, a steady rhythm has to be maintained.

+1

I agree with 44man.

[spurrit]

BTW, if any of you has a bottom pour pot for sale,(cheap) please let me know.

[HeavyMetal]

Here's what I think: when you work with single and double cav molds no problem, move to a 6 banger and whoops there it is!

6 banger Lee's molds are notorious for shedding heat in a hurry. If your running a fan in the casting area to keep yourself cool you'll compound the problem!

I think your mold is cooling to fast and you need to cast faster. I will ask what type ladle your using?

If it's to small and not a bottom pour type like the rowell or lyman / RCBS ladle then your shooting yourself in the foot and simply not getting the cavities filled completely!

Check some of the easy to size boolit under a magnifiying glass and see if they are completely filled out! My guess is they are not!

Step up and buy the small Rowell ladle, either the number 1 or 2. these will handle 1 to 2 pounds of lead respectively and allow you a good hot supply of alloy for all 6 cavities in your mold also don't be afraid to dip a corner of the mold in the alloy every other filling just to keep it up to temp!

If you do this and mantain a steady heat range, 690 to 725 degrees you should not have a problem with fill out or undersized boolits!

My answer to your specific question? No heat doesn't matteras long as you have everything at a temp that will allow the alloy to flow correctly and keep the mold at a proper operating temperature to fill correctly!

[Boerrancher]

When I started using lee moulds it was a learning curve for me as well. I had cut my teeth on the Lyman moulds, which hold their heat longer than the lee moulds do. I for a long time got crappy looking under filled boolits and finally I got to thinking about what I was seeing and doing. I turned the heat up a bit on the pot, and would as heavyMetal stated dip the corner in the pot when it would look like my mould was starting to cool off too much.

Best Wishes from the Boer Ranch,

Joe

[spurrit]

Here's what I think: when you work with single and double cav molds no problem, move to a 6 banger and whoops there it is!

6 banger Lee's molds are notorious for shedding heat in a hurry. If your running a fan in the casting area to keep yourself cool you'll compound the problem!

I think your mold is cooling to fast and you need to cast faster. I will ask what type ladle your using?

If it's to small and not a bottom pour type like the rowell or lyman / RCBS ladle then your shooting yourself in the foot and simply not getting the cavities filled completely!

Check some of the easy to size boolit under a magnifiying glass and see if they are completely filled out! My guess is they are not!

Step up and buy the small Rowell ladle, either the number 1 or 2. these will handle 1 to 2 pounds of lead respectively and allow you a good hot supply of alloy for all 6 cavities in your mold also don't be afraid to dip a corner of the mold in the alloy every other filling just to keep it up to temp!

If you do this and mantain a steady heat range, 690 to 725 degrees you should not have a problem with fill out or undersized boolits!

My answer to your specific question? No heat doesn't matteras long as you have everything at a temp that will allow the alloy to flow correctly and keep the mold at a proper operating temperature to fill correctly!

I've noticed that the crappy bullets are generally in the 3 cavities nearest the handles.
And I'm using a tablespoon for a ladle; money ain't exactly rolling in as I recover from spinal fusion.

[44man]

I had to empty my broken Lyman pot so I decided to drop in the thermometer after it fully heated. WOW, it buried the needle at 1000*!
Looks like it goes in the trash. It is so old when I called Lyman for a new thermostat, she laughed at me. :mrgreen:

[Boerrancher]

Spurrit,

When you said, "I've noticed that the crappy bullets are generally in the 3 cavities nearest the handles," That told me that you were probably always filling the cavities from the front of the mould to the back. Hence, The last three cavities have the longest time to cool. It is not as critical with 2 cavity, but above that you need to alternate your filling direction. Fill front to back, and then back to front. This should help keep your mould temp a tad bit more even.

Best Wishes from the Boer Ranch

Joe

[HeavyMetal]

Spurrit:
The right ladle is everything when dealing with 4 and 6 banger molds. Ya I feel the money thing to right now.

Boerrancher's has it right fill from rear to the front! I cut a groove in my ladle to set on the sprue plate and then slide forward while tipping the ladle to fill the mold. A little angle (up) on the "nose" of the mold will help control pouring alloy into cavities your not yet reaching yet!

Seems to me I had an extra ladle laying around my garage someplace (?) IF I can find it I will donate it to you. As I recall it's nothing to write home about but it has to be better than a spoon!

If I find it this week end I'll PM you for an addy to send it to.

[spurrit]

Spurrit:
Boerrancher's has it right fill from rear to the front!

Last time I did that, she got a bladder infection! Ewwww! Anyways, thanks for the ladle, I appreciate it!

I tried filling from front to back, back to fonte, alternating, etc; it just caused me to get crappy bullets in different cavities!

[Baron von Trollwhack]

Likely a $5 lee thermostat would work. BvT

[spurrit]

I think the mods should yank my title of "boolit master". I'm more like the crud floating on top!

[bobk]

44man,
+1 on what BvT said. Any rheostat, potentiometer should work, with a high enough amperage rating. Or send it to spurrit, so he can fix it and use it. If you absolutely have to throw it away, throw it at me!:grin:

Bob K

[TAWILDCATT]

LEE sells their thermostat for $5.00 others have used it on lyman and Saeco.I have to get me one for my old saeco.I use the 20# Lee botom pore.their about $80 from Midsouthshooters.com
I modified most of my multi cavity spru plates by milling a ball mill from on end to other IE between holes.then you just hold the spout open and get a good spru.
got to do it to my Lees.:coffee::violin:

[hotwheelz]

I dont know for sure if temps affect boolit size but from what others are saying here I would agree it does, but what I do know is I have had a lee 6 cavity mold that would drop diff size boolits all the time it seemed that there were 2 really fat cavitys this was a 45 200gr swc TL maybe something else to look at..