How hot do you want your lead?

[Bohica793]

I have my PID set for 675 and everything I am casting comes out silver and at or .001-.003 over stated mold size. The only time I have bad pours is when my mold gets too hot or cold. The PID has improved my casting consistency immensely.

[jmort]

I have mine set at 680 and if I preheat molds on hot plate it works well. Not too cold here in So Cal so not sure that would work in colder climates.

[prs]

I mostly cast pistol boolits and I go for volume. Perfect, well, they are very good. I have a very low cull rate. I have to adjust my PID depending upon how cool the outside air is as the fan brings it across my casting station, I like 710 on warm days and 730 if pretty cold. I do heat the mold on a hot plate and get it too hot on purpose, then let it cools as I do the preliminary casting before keeping the produce. I pace myself so as to keep the mold at point where the boolits are just slightly and evenly frosted, that seems to give me the best detail without under sizing the produce. With a 6 cavity aluminum mold, my first filled cavity is just freezing as the last pour is finished.


John Boy has me curious; a 5 second pour, on one cavity? Or is it 5 seconds to fill 4 or 6. Or is that a ladel fill of a large rifle boolit where the ladel is kept on for 5 seconds in the quest of casting boolits of perfection?

prs

[bangerjim]

Actually, 675 is NOT too cold at all for an alloy that melts at 575, but it will likely make smaller bullets. Sometimes we NEED to do that, as in getting a fat bore rider to chamber in a certain rifle.

General pot temperature rule for any alloy has been described in books since the invention of cast bullet manuals: 100 degrees above full liquidus. Give or take depending on exactly what you need the alloy and mould to do. Using "the force" is fine if you have an unusual concentration of Midi-Chlorians, but for the rest of us, using a thermometer and the known constants of metal alloys is usually best for getting the same results every time. A notebook IS handy for this.

Bangerjim may not take a very scientific approach to his casting and yet it works for him, HOWEVER he doesn't post much about shooting cast in rifles for competition-grade accuracy or extremely high velocity. Consider the context of the advice given. For most pistol work, it really doesn't matter that much as long as you can cast a bullet with a good base. For other things, bullet quality and repeatable casting techniques matters a great deal. Context is always an important consideration when reading generalized advice.

Gear

Exactly right. I do very little casting for uber-velocity/accuracy in rifles. Most of what I do is for paper target and plinking. I do not hunt. All my boolits squeeze thru my dies per the size I need for the barrels. Some go thru firmly, some squeek thru. All end up at the size I want, frosty or not. And I do not worry about weights that much, as I do little competitive shooting. I do my hunting at the meat markets or Outback or Ruth's Chris. Perfect targeting.....every time!!!

All my pills are sized, PC"d, and sized again to the correct dimention.

bangerjim

[44man]

I have no idea what my mold temp is actually. My little mold oven is made from an electrical box with a BBQ thermometer in the top and I heat soak with that at 500* so the mold could be hotter.
My first boolit will be perfect.
Since the mold sits on the bottom of the box on the coils, I have no real idea. I know it works.

[JeffG]

Clinton,

I get my tin ingots from Rotometals, which should be linked at the top of the webpage. If you buy $100 worth, you get free shipping. That amount will last a long time.

So any solder that says "lead free" is what I want? I know nothing about solder.

[10mmShooter]

I agree on the cool off period after filling the mold it can vary based on the alloy temp going into the mold and what temp the mold is at so you have to adjust your cool down time prior to dumping I watch how my sprue puddles cool and how the bases look as I drop them and adjust for more cool time or less you also have to watch the sprue plates they can get to hot as well and cause smears, I use a mix of RCBS, Saeco iron molds and a brass mold or two.

I do like my thermometer, I get best results in the 675 to 705 range, if I'm on the low end, I slow my pace to allow my Lyman Mag20 to recover, and if I'm on the high end , I throw more lead in the pot to cool the temp. So I'm always making subtle adjustments in my cadence or adding lead to the pot. I run the pot with the dial on 9.5 and never move it. Also I never never ever let the pot go below 70% full. Always keeping 15 ish pounds of lead in the pot at temp, helps the temp recover when new lead is added as well as keep the lead flow pressure the same at the spout. Just what I do.... your results may vary

Also I have learned over time casting not to fight a mold, you can try to play with alloy mix and temp to get a 1/1000th here or there but at the end of day the best thing is either have the mold modified or have a custom mold made that will work for you and your alloy.

I require all my molds to drop at least 2/1000ths over the dimension I'm sizing down to too, this allows the sizing die to do its thing and erase any defects in the bullet diameter. In some cases the mold will drop correctly right out of the box, in other cases I had to work on the mold a bit to get it to behave as I wanted it too. In one case my .44 Henry likes .432 sized bullets, so I needed a mold to drop at .433+ no choice here I had to order a custom mold. In other cases I can just enlarge the rear most driving band and the dimension I'm looking for.

[Ken O]

I have sharpie pen marks on my Lyman thermometer face for what where the molds drop right. They change, I think the thermometer has changed over time, because the marks are higher and higher.

My unscientific way to get the right temp, its to get it to frost, then back off just under the frost temp.

[Clinton]

Added 2% tin and took my temp up to 740. It's still dropping small, possibly even smaller. Rear driving bands mic at .308 and the nose is .298-.299. I'm really beginning to think it's just the mold. I was casting two different 312 Lee molds at the same time and they're coming out at .313. I could beagle it but I'm wondering if I'd run into problems seating gas checks then.

[rsrocket1]

I used my beagled C312-185-1R for the first time last night. Out of the box, it was dropping at .313 on the front bands and 0.314 on the rear bands. When I was seating the Hornady 30 cal GC's on them with the Lee push through sizer which was 0.314", the bottom half of the bottom band would come through shiny meaning it was the only part of the boolit that was >0.314".

After beagling with 2 strips of the copper foil tape stacked on top of each other on either side of the mold, the fat dimension of the boolits were 0.3175" and the narrowest diameter of the boolits were 0.315 so even the "non-beagled" dimension grew a bit. Pushing them through the sizer resulted in shiny surfaces on all bands and putting the gas checks on the fatter boolits was still no problem.

I was experimenting with temperatures anywhere from 650 to 750. I also experimented with varying methods of heating up the mold from my usual dipping the corner in the melt until the lead no longer stuck to dipping a big section of the mold for a very long time (until I was convinced the mold was almost the same temperature as the melt. That resulted in some interesting pours. When I cut the sprue and tipped the mold over to drop it into the pot, molten lead poured out of the cavity. I won't be heating the mold that much again.