Mold Temp - Pot/Alloy temp

[KHornet]

After well over 50 years of casting, I have come to the conclusion, that all molds are female, and need to be treated appropriately. Years back I wanted shiny bullets as they dropped from the mold! Back then I cast out of an old cast iron frying pan on the kitchen stove (I have a very tolerant wife who puts up with such things). Some place along the line maybe 35-40 years ago, I read that it is best to have a bit of frosting, and sort of adopted that, and by that time I had a 10 lb. electric, and was running a bit hotter. By that time, I also learned that timing and tempo counted a great deal. But that really took a long time to sink in, and I often got in a hurry. I also learned then that not waiting until the sprue was well hardened fully that I did not get consistant bases;. Speed kills, and makes inconsistent bullets. Bullplate helped me when that came along. Way back, about all I could afford was single cav bullet molds. That's when I learned that they are all female, sensitive, different, etc., and the bigger the bullet, the more time it took between. All molds are not created equal, and there were no custom mold makers back than that I can now, at least remember. Casting has come a long way in the last 20 or 25 or so years, as this thread proves, and there has been a lot of acquired learning in that time frame. I expect that there will be developments in casting in the next few years that we can not even imagine at the present time. After well over 50 years of casting, I still have a lot to learn (And not just about casting).

 

[Mike W1]

I would think that proper mould temperature would be most important and maybe even obvious. The two things that were most important to me were the need to have a steady even flow into the mould and to hit the center of the sprue hole. If one or the other was not done properly I didn't have a filled out base on the bullet. Noticed that many years ago on rifle bullets and haven't seen it dwelt on by many writers.

 

[Rick]

Mold temp is very important for well filled out bullets including the base, not too hot or too cool. Sprue plate temp is also important for good bases, very difficult to get good bases with a plate that's too cool just as you'll not get good hollow point noses with the pins too cool.

It's not necessary to hit the center of the sprue hole for good bases though. What is needed for good base fill out is the plate up to temp AND pouring enough sprue to give the solidifying bullet inside the mold enough molten alloy to draw from. That's part of the reason I ladle pour holding the mold over the pot and keep pouring after the cavity is full letting the alloy run off the plate back into the pot. Then I keep pouring going back over the sprue holes before the sprue's start to solidify to assure all bullets have plenty of molten alloy to draw from. Hot sprue plate & well filled out bases.

I only make one inspection of bullets while casting, when I open the sprue plate and before opening the blocks I inspect the bases. There will never be an easier time to see any base that isn't 100% filled out all the way around, it will show up like a neon sign. Any I mess up on goes straight into the sprue pile.

 

[Mike W1]

Personally when my sprue plate gets a little too hot I turn on my cooling fan. And if the mould's hot enough I can leave a pretty small sprue and get good base fill. I've also used aluminum sprue plates with good success. I do agree that when you open the sprue plate up is the time to inspect the bases.

 

[James W. Miner]

I heat molds in a little mold oven on a hot plate to 500°. Soaked at that. First boolits are perfect but the mold will get hotter. I slow down. I want little cuts on the sprue not a swipe on molten lead with a glove.
I look at the sprue and judge the cutting. I don't use a fan but will wave the mold 4 to 5 times to cool. I have been laughed at but it works. Swing the mold and soon you will know how much for each pour.
I make my own molds but have many factory molds and all work the same. I need no notes for any. I have a few hundred molds and all work. Even cheap lee molds make perfect boolits.
Relax when casting, no hurry at all. if you cast 1000 and toss 500, where are you? I dump a 20# pot to the bottom without a reject.
I will cast a mold, go out the door to pee and come back to make the next perfect. You get too anal over casting.

 

[Rick]

You get too anal over casting.

Too anal? Too anal for whom? Someone doing things the way they enjoy doing them and getting the results they are happy with is certainly not being anal for them! Too anal for someone else? Very possibly but they aren't forcing or even suggesting that someone else do it their way, simply describing how they do it.

 

[62chevy]

By preheating my mold most of the time I get perfect bullets on the first cast. When I don't I just pull a Rick and let the lead pour all over the sprue plate with my ladle. I have never checked what the mold's temp is as long as bullets are filled out and not to frosty I'm good.

 

[James W. Miner]

To cast 500 scuds in the time I make 100 is anal! Speed does kill. Casting is easy and what I read on every site is for the most at the fastest.
I am anal at the most because I do not want a bad boolit---EVER.
I might describe myself first. yes my friend, I am anal more then anyone but know how to fix it if a boolit comes out wrong.
Making my own molds has been a crazy path.
I have fooled with lead casting over 66 years. I really am anal.
I think I was 12 when I made a jig mold by hand for fishing lures. Set a hook and cast many jigs. I still have the original that makes 4 at a time.
Today anal is to make more then a mold can do within time.
I hate casting and loading but I am anal over every one so accuracy is foremost, Not a ton from a progressive press that makes noise.
My anal is perfection over speed. Tell me your mold must be such and such over another so you keep notes, you are anal.
A million posts that say "I cast at 600°, balderdash, cast hot to frost, more balderdash.
Anal is good if you know how to use it.

 

[Rick]

Jim, to quote a great man . . . . "There you go again".

The conversation in this thread is about casting techniques regarding pre-heating the mold and originally also pot/alloy temp. Not a single word in this thread about speed casting until you changed the subject in an attempt to make your anal statement have some validity. I suggest you read post #1 in this thread to get an idea of the subject being discussed.

Again, anyone casting the way that pleases and interests them is doing it correctly for them regardless of someone else thinking it is or isn't anal. More power to them, I hope they keep doing it their way for many, many years to come. Same goes for you, keep doing it the way that pleases you but please do so without trying insult others because they aren't doing it your way.

As a side note, I love casting. That's why I do it.

 

[James W. Miner]

I want all to do the best. if you make more boolits then I do and all are good, so be it.
I have not insulted a single person. Please do not go that way.
You must find your way.
I want all of you to have the best Christmas ever. Merry Christmas to all of you.

 

[Ian]

Merry Christmas to you, too, Jim, and glad to have you here. By the way, how long have you and Rick been married?

 

[Tony]

LOL!!!!!

 

[Brad]

When I started using a ladle and casting the way Rick described my base fill got better. Much better. My reject rate dropped too.
I found that what I thought was a hot mould was only luke warm.
I cast the way I do because it works for me. I get plenty of good bullets. I enjoy myself.

Let's keep things positive guys. We can agree to disagree. What matters is doing so in a polite, respectful manner. One man's anal is another man's search for perfection.

This site was created, in a large part, to rise above pettiness. Just because someone else does things different doesn't mean they are a lesser individual. I have been on other forums where I was called out for shootng wimpy loads. I have been on forums where I was called out for not shooting at proper distances. In the end I ignored all that BS because I don't shoot to make others happy, I shoot to make ME happy.

Keep things positive, please. Let us know what you do but if others do things in a different manner either keep it positive or keep quiet. Enough said?

 

[Ian]

I bottom pour something like 99 out of every 100 bullets I actually shoot. I also balance a huge molten sprue puddle on the plate, as much as it will hold without breaking over the sides and running everywhere. I still get occasional hidden bubbles (some not so hidden) in the bases if I don't break the top inside edges of the mould blocks with a file. The cause of the bubbles is turbulence or the "dribble effect" as I call it of the stream breaking into drops as it falls inside the cavity. If the mould is making little bubbling sounds as the cavity fills, it's bound to have some voids. The high volume, low pressure stream from a ladle seems to mostly cure this, as does proper adjustment of the stream from the bottom pour together with just the right head pressure and just the right fill angle, but still it's tricky with a bottom-pour to avoid bubbles in the bullets altogether. Still, mould temperature, sprue plate temperature, and alloy temperature are the things I pay the most attention to when casting, if those aren't correct for the circumstances, and kept correct once found, no pouring technique can fix the problems that will be at hand.​

 

[Brad]

Speaking of breaking the top in side edges of the blocks, why isn't this done by the mould makers? I find it is needed on almost every mould. Worst I had was my HM2 9mm mould designed by fiver. First 500 or so bullets had at least a 50% reject rate due to rounded bases. Filed a bevel on inside edges of blocks and things got better. Filed a bit more and now bases are all nice and fully formed.

 

[Ian]

The worst ones for me were Tom's moulds. Those things are machined so flat, polished so well, and made out of such good materials that the sprue plate and block tops are absolutely air tight. I don't remember now who it was who suggested breaking the edges, but I tried it on a Lee mould and boy was I a happy camper. Then I did it on my expensive, custom moulds and what a difference!

What I wish mould makers would do is machine some real vent lines (not just a few, microscopic cat scratches) on the top of the blocks like BRP used to do. Wait, LEE just started doing that on their new moulds.....when will the rest of the manufacturing community catch on?

 

[Ian]

Here are some of the moulds I have that have the vent lines on the top. The 2C in photo upper with the dense lines is a BRP, the lower left is a custom one-off with vent scribes cut at my request.

 

[freebullet]

Sheesh....I always put the rounded base boolits in a separate pile to use as my top secret cast boat tails. Yall really remeltem or never get them?

Top secret cast boat tails=
You take a friend to the range fire a nice group let him shoot a group but provide the top secret cast boat tail loads. It can be a handy tactic for punking your bud or teaching a new caster.

 

[Brad]

Ian, I never bought a mould from BRP and I sure wish I had. I looked at them but never pulled the trigger.

 

[Ian]

FB, rounded bases are the first thing I look for when the sprue plate comes open and are cause for an automatic cull and technique adjustment. Generally I don't get them, and all of them that I do get go straight back into the pot.