Home Forums Reloading Bullet Casting Mould Heating.

I have three large moulds I am trying. I normally use two cavity moulds and just set them on the pot but these are bug four and five cavity brass and aluminium moulds and I an having a hard time getting them hot enough to cast.

So, my question is how do you heat your moulds and what is the temperature you want to get them.

I use an electric hot plate and keep mine in the 600-650 degree range depending on alloy,# of cavities and size of bullets I'm casting. Saves time and reduces the cull count immensely.

Kind of what I was thinking of trying. These are all 45 moulds and are huge. Thanks

On mom's electric stove I set the eye on 2 maybe 2 1/2 while the lead is coming to temp.

I picked up a hot plate at a yard sale cheap and it's been one of the best investments I've had.

I use to hot plates to get any moisture from the mould out as the alloy comes up to temp.
Dunk the mould in up to temp alloy; pulling up to check until lead rolls off the mould (usually about eight to ten seconds), begin casting.

Four and five cavity moulds should often need to set a sequence and once up to temp stay hotter and set longer than any two cavity mould of the same material.
When using brass or iron with aluminum moulds, I cast twice in aluminum for once in the brass/iron.

That's what I do - set it on the burner...

Hot plate will be there Tuesday from Amazon. New 20 bottom pour lead pot will be delivered Wednesday. Fifty pounds of softer lead delivered last night.

I wish I knew someone around here who has a hardness tester and could test some of my bullets. I would like to know just how hard they really are.

I float my molds on top of the molten lead until it falls away cleanly, then start casting. The first few dumps I don't even look at and when they are filling properly I'll start heating the second mold.

I have a tester Scott, Send them to me I would be happy to help you out.

The Lee Hardness tester is a good investment.

The hot plate was a great investment for me. Especially for the multi-cavity moulds.

I've toyed with the idea of getting a hardness tester but still use the thumbnail method an old bullet caster showed me 30 years ago. A thumbnail of normal hardness will easily dig into soft lead, 5-8 BNH, will lightly mark WW lead, 11-12 BNH and will not mark linotype, 20+ BNH. I know this is not exact
but will get you close on an undetermined alloy.

I can scratch it but not much. Sounds like I am in the 11-12 range. Thanks mart.


I lee hardness tester is on my wish list but I have a lot of wish list to wade through.


I'll take you up on that off er paul. Do you by any chance shoot and 45 cal. I would me happy to send some powder coated for you to play with.

Sounds like WW material to me or an alloy of the same hardness as wheel weights. Like I said, it's not exact but it gets me close when I find an ingot or old batch of bullets I forgot to mark.

You'll definitely know linotype when you run a thumbnail over it. It's like running your thumbnail over glass. It just won't mark at all.

Much of it is 7% tin, 93% lead.

I do have some wheel weight and will try a comparison.

I cast wheel weights as is. At moderate velocities, say under 1200 fps, they are hard enough. Above that, I drop them from the mould into a pail of water. My 45 Colt loads are mostly 650 - 800 fps or so. My 405 grain 45/70 bullets go into the water, even though I usually keep the velocity under 1350 or so. No problems with leading on either.

The 45/70 bullets hardly deform hitting the rock fines pile (tailings) and a bud of mine figured the water quenching likely gave them a hardness of about 20-22. They work well, and are great plinking bullets.

Gueßsing you are casting for old slab sides, so you velocity is likely under a grand. You should be good to go.

I set my 4 cavity NOEs and 6 cavity lees on top of the pot, and use the dip test to tell if they're hot enough to begin. I just pour, dump the cold bullets back in the pot with the sprue, and repour immediately. I dump the first several back into the pot without even looking at them. As soon as the wrinkles disappear, I start casting. I tend to run my molds fairly hard, using long sessions with 1 or 2 molds only. Since I water drop, I'm pulling bullets as soon as the sprue visibly cools, dumping them, and pouring again.

I used to worry about bullet hardness, till I started powder coating. Now I don't care (for pistols anyway). My preference is to use a cheaper nearly all lead alloy with sufficient tin for fillout.

what about brass moulds-what temps should they be heated to? i know warpage can be an issue.

i've got a brass 2-cavity 45/70 mold on order from accurate and don't want to do anything stupid to damage it.

Have you tried that charcoal artist pencil scratch test?

http://castboolits.gunloads.com/archive/index.php/t-75455.html

Somewhere in that thread there is a link to a chart.

I know about it but I have never tried it. Think I will get the Lee tester when thingscalm down with me son.