How low can I go?

[Sticky]

With my casting pot temp? I have been using COWW, a tiny bit of tin and casting the Lee 3092305R, which really likes to be cool. How low can I run my pot and still effectively pour a good boolit? I know I can cool the mold, going to play with that next time around, but I am spending too much time waiting for it to cool and not enough pouring with only a single mold.

I have a couple more coming to assist me with rotating molds, which I know will help. I have run the pot as low as 625F and still had consistent pours and good looking boolits, but I was afraid to go much lower. When I add an ingot, if the spout (bottom pour) cools too much and the temp gets below 600, I have to wait for it to recover a bit.

Just curious if there is an effective lower limit that I should mind?

[swheeler]

Sticky your mold temperature is the problem, too hot, try the Bruce B method. A search will turn up the info you need.

[44man]

That is awful cool for lead. I cast everything at about 750. The control is your cadence. You do not need the sprue to harden in an instant.

[country gent]

All you can do is experiment a little at a time and see what works best. If adding a bigger ingot is causing problems cast a smaller ingot and add more often. Also set a few ingots on top of pot to preheat and add from these as the pre heated ingots will be much closer to melt not shocking as much. Another trick when waiting for a mould to cool is to leave it opened up, this increases the surface area for heat to work out of it. closed up it dosnt allow this surface to loose heat as well. Sometimes a damp cloth of fan helps alot with a mouuld that wants to run cooler also. Cast in the winter when ambient temps are much lower also.

[Sticky]

Thanks for the feedback all, I realize my problem/concern is primarily mold temp, that lee mold likes to be cool... really cool, or it starts frosting quickly. I will try the fan or wet towel trick next time around and see if that helps me. I am casting in an unheated garage, temps in the 40's probably in the garage, perhaps lower on a cold day.

I have worked out the ingot issue, that wasn't really a 'problem', more of an observation as to how low I could go before things stopped flowing.. lol. I do heat them on the edge of the pot, or just got a hot plate, going to use that to warm them now. I ran the first run of these at 700, but they frosted right away, so I ran the second at 625, then the last time I cast with the pot at 650, took my time between pours to let the mold cool (opened up) and the boolits came out great, just not fast enough for me..

I'll work on the cooling and when I get my second mold up and running, I know that will help me too.

[Yodogsandman]

Sticky, are your temperatures taken with a thermometer, digital temp gun or a PID? If a thermometer, have you checked the temp using boiling water?

Try casting about 100*F over the temperature that your alloy melts at.

[Sticky]

Sticky, are your temperatures taken with a thermometer, digital temp gun or a PID? If a thermometer, have you checked the temp using boiling water?

Try casting about 100*F over the temperature that your alloy melts at.

I have a lee 4-20 that I PID'd, the sensor is not actually in the melt, but sandwiched between the bottom of the pot and the outer underskin, in an aluminum block and in contact with the bottom of the pot. It responds very quickly to pot temp changes, but... I have not yet verified the melt temp vs the PID temp, I will do that next casting session to be sure there is no offset (there possibly could be and I can program that in). Still learning the process and it's nuances..

At 650F, I am close to 100 above my melting point, it is mostly pure coww lead, already smelted and a pinch of tin added when needed.

[Yodogsandman]

Your alloy would probably melt at a little over 600*F (for reference).

[JWFilips]

I like to run From 700 to 725 Deg At least that works for me . Under that I get nice boolits but they are low weight.... Over this I get ok boolits but they are undersize ...Not sure if this makes sense to you...But This is just the way I do it .
(My alloy is 50% COWW + 50% Pure lead with an add'l 2 % tin)

[454PB]

Frosted boolits are GOOD! If the appearance bothers you, it can be wiped off after the boolits are seated.

[Sticky]

Okay, ventured out to the garage this afternoon and found that my alloy temp is a little higher than what my PID is reading, so I will recalibrate that (once I find the programming book for the PID.. lol). So, I decided to break out my Mihec 452200HP mold (Cramer) and try my hand at something that likes some heat.

It sure is easy to cast HP's when you have a fine piece of work like that... my first few pours were rejects, but after that I got things rolling along very well.. Ran the pot at 700 (alloy closer to 750 in reality), heated the mold up on the hot plate and cranked out a bunch of boolits in no time at all.

I can see the extreme differences between the Lee 309230 mold and Miha's mold as to how they like to run. Who said hollow points are tough?

[Sticky]

Pics.. sorry, crashed the laptop trying to upload these beauties...



Good ones...


Bad ones and maybes....



This brings me to another question... I have a lot of them lately... I had a couple handfuls that didn't quite fill out the base to create a nice sharp corner on the trailing edge of the boolit.

Are these worth the effort to coat, size and load, or should I just remelt em next time around?

[Errokk]

As few in number and when In doubt, re melt and cast again imo. Good lookin boolits!

[Sticky]

Thanks Errokk, that was my thinking too.. easy enough to pour em again... and there were few rejects, over half of them were me learning my technique for filling the mold, the rest were not quite filled out all the way on the very base, again, probably not getting my stream in the hole, but off to the side a bit and dribbling the alloy in. After a while, I got a technique worked out that seemed to be consistent.

[btroj]

The ones with a rounded base, what are your accuracy needs? If 10 yards then shoot em, if you want top accuracy melt em down.
I will admit to having fired more than a few rounded bases in my 1911.

If you keep getting rounded bases try lightly bevel ing the top, inner surface of the blocks. A very light bevel lets air escape and stops that rounded base. Been there, done that.

Did I mention a light bevel? Make it too much and you get base fins. Those are bad.

[Sticky]

I always want max potential accuracy, so... in the melt they go.. lol

I did notice that it was mostly happening on one cavity, nearest the sprue plate hinge, but I honestly think it was my not getting a good pour in that cav at first til I switched up my filling sequence and then it seemed to go away. Also noticed that the hotter the mold, the better it was... still learning...

[btroj]

A hot mould is a must for good bullets. Don't forget that unless you keep adding heat to the mould it cools off. That heat comes from the lead. Melt temp needs to be high enough for good flow, good fillout, and good heat transfer. Don't go too hot or you can oxidize out the tin and get moulds too hot leading to lengthy hardening time in the cavities.

it is all about balancing the various needs of the mould and finding a rhythm that works for each mould

[Sticky]

A hot mould is a must for good bullets. Don't forget that unless you keep adding heat to the mould it cools off. That heat comes from the lead. Melt temp needs to be high enough for good flow, good fillout, and good heat transfer. Don't go too hot or you can oxidize out the tin and get moulds too hot leading to lengthy hardening time in the cavities.

it is all about balancing the various needs of the mould and finding a rhythm that works for each mould

I can see that clearly with the vast differences between the 2 cavity aluminum mold from Lee for the 309230's and the 4 cavity brass Mihec mold for the 452200's. One likes it cool, the other likes it hot. I ran my alloy at 750, preheated the mold to 600 (as noted on the hot plate dial) and it started casting good boolits very quickly. I saw an improvement over time as I gained some heat in the mold after pouring a few rounds, the fillout was better on the bases and much more consistent with the added heat to the mold. Really had no issues with the hollow points, they just seemed to work well right off the bat.

I would start to get a little frosty and it was time to rest the mold back on the hot plate and cleanup and remelt some sprue and refill and flux the pot a bit.. my rhythm was pretty good near the end of my session.

Thanks for the guidance all, your input is very much appreciated!

[454PB]

Touching the filled mould to a wet cloth will allow you to control mould temperature without slowing down.

[Sticky]

Touching the filled mould to a wet cloth will allow you to control mould temperature without slowing down.

I am going to try that technique next time I sit down with that Lee 309230 mold.. it should be just what I need to keep a more steady rhythm going with it. I really didn't need to cool Miha's mold, it just ran... good!