How fast do you fill a cavity.

[Colorado4wheel]

So how fast do you fill the cavity of your molds? What difference does filling slower or faster make? Particularly with a 9mm mold. Using a 4 cavity 135gr mold if that matters, which I know it does.

I am thinking I am filling the mold too fast. But I am not really sure how to tell.

[btroj]

I like to fill a mold fast. More important than speed in many cases is how. Straight in, swirled in, mould level, mould tipped to one side. That can make a huge difference in some moulds.

Play around with it some, each mould has likes and dislikes. Find what that mould likes and then just keep it happy.

I know this sounds corny but it is how I do things.

[Jkallen83]

btroj said it right....

i am new to casting, less than a week. i learned that PURE lead seems to shrink and dont cast too good at all.

got some lead that had been mixed for bullets and its great. my mold works best poured fast with the mold level....

try different things, just about everything i did changed the outcome in how the bullets turned out. once u get it figured out what works for u, its a breeze...


by the way, i learned really fast one thing that i aint read no where on here yet.....DONT ACCIDENTALLY TOUCH THE MOLD after casting several rounds. its is HOT!!!!! lol

[jmsj]

I like to fill a mold fast. More important than speed in many cases is how. Straight in, swirled in, mould level, mould tipped to one side. That can make a huge difference in some moulds.

Play around with it some, each mould has likes and dislikes. Find what that mould likes and then just keep it happy.

I know this sounds corny but it is how I do things.
I don't think this corny at all, I think you are spot on.
jmsj

[Le Loup Solitaire]

Sound advice from btroj....each mold has its own personality so you have to try a few ways to do it to see which one works best. Sometimes if the pour stream is too thick or too fast you can trap air that effects the fillout. Height also can play a role if you are using a bottom pour. Its a good idea to keep notes on each mold otherwise unless you have a really good memory...with a lot of molds it can become a jumble. Advancing age makes it worse, so jot down what each mold likes or dislikes on a 3x5 card and life will be a little easier. LLS

[BulletFactory]

I let my dentist worry about such things.

[Jkallen83]

i also found that hotter lead works better for me. i melted the first time, the second time i increased the heat and the hotter lead seemed to give more time before they set and filled the mold better...

just a tip i thought about that helped me... but i also read that u can have bad effects if its too hot, so gotta find that happy medium.

[stubshaft]

I'm with Btroj on this one. The mold will tell you what it likes and I try to remember what mold likes what method. After a while you just pick it up and instantly remember how it likes to be used.

As far as heat Jkallen, I've been casting for over 40 years and never found a use for a thermometer. I would probably say that I cast with a relatively hot melt, but believe that a consistent tempo is more important than watching a thermometer.

[geargnasher]

I like to fill a mold fast. More important than speed in many cases is how. Straight in, swirled in, mould level, mould tipped to one side. That can make a huge difference in some moulds.

Play around with it some, each mould has likes and dislikes. Find what that mould likes and then just keep it happy.

I know this sounds corny but it is how I do things.

Just in case no one else agreed with you, I do :grin:

Gear

[Recluse]

The bigger (as in 44 or 45 or larger) the cavities, or the longer (30 cal, cruise missiles, etc), the faster I like to fill them.

Also found that ladling works better for me with the big/long cavities than bottom pour.

:coffee:

[Bret4207]

i also found that hotter lead works better for me. i melted the first time, the second time i increased the heat and the hotter lead seemed to give more time before they set and filled the mold better...

just a tip i thought about that helped me... but i also read that u can have bad effects if its too hot, so gotta find that happy medium.

It's keeping your mould hotter. Melt temp vs mould temp, 2 different things.

[Boerrancher]

I fill fast, run a hot melt, and cast at a fast pace. I like my boolits to come out frosty, at least on the base, and better if the whole thing is. I use a 50/50 alloy, and have noticed over the years (35 years this summer) of casting, that when I get boolits with a uniform frosting, I don't have to worry about them not being filled out, or being different weights. Shiny boolits, 255 gr 454 dia can weigh any where from 250-255 grains depending on the temps of the mold and melt. Once they start frosting they are a consistent 255 grains. Are they as pretty when loaded as the shiny ones? No, probably not, but I want consistency because that translates into accuracy. Fill the mold fast with hot melt and leave a generous puddle on top of the sprue plate. Cut the sprue when the puddle turns from shiny to a dull grey, drop the boolits as fast as you can and get the mold refilled. Once the mold is up to temp you will have a good fill out on your boolits.

best wishes,

Joe

[Larry Gibson]

The bigger (as in 44 or 45 or larger) the cavities, or the longer (30 cal, cruise missiles, etc), the faster I like to fill them.

Also found that ladling works better for me with the big/long cavities than bottom pour.

:coffee:

+1 along with the comments about hotter. I've found it is important to get the molten alloy into the cavity as quick as possible, especially with larger bullets. Bullets of 300+ gr I pour with a ladle that I've also opened the spout on.

Larry Gibson

[Shuz]

Another thing to consider with a bottom pour furnace is the level of the melt. I find that I get the best fill-out with the 20 lb pot, from full to about half full. I attribute this to what I call "head pressure". I also fill as quickly as I can, and keep my temperature from 700 to 800 deg.F. Casting in tandem with two moulds also speeds up the process because you are busy with one mould whilst the sprue is cooling on the other.

[jdgabbard]

I fill fast, run a hot melt, and cast at a fast pace. I like my boolits to come out frosty, at least on the base, and better if the whole thing is. I use a 50/50 alloy, and have noticed over the years (35 years this summer) of casting, that when I get boolits with a uniform frosting, I don't have to worry about them not being filled out, or being different weights. Shiny boolits, 255 gr 454 dia can weigh any where from 250-255 grains depending on the temps of the mold and melt. Once they start frosting they are a consistent 255 grains. Are they as pretty when loaded as the shiny ones? No, probably not, but I want consistency because that translates into accuracy. Fill the mold fast with hot melt and leave a generous puddle on top of the sprue plate. Cut the sprue when the puddle turns from shiny to a dull grey, drop the boolits as fast as you can and get the mold refilled. Once the mold is up to temp you will have a good fill out on your boolits.

best wishes,

Joe

I think they're prettier when frosted. Gives it more of a "Hey, I'm not jacketed!" look.

[QuickRick]

If we're talking how fast do I fill each mold cavity, then it's as fast as the molten metal temperature allows. Going from cavity to cavity I try not to hurry things. I just remind myself I am dealing with 750 degree molten metal. Besides, when using the Lee six cavity molds I prefer, bullets pile up very quickly without a conscious effort at speed.

[prs]

I agree with the corny method too.

prs

[runfiverun]

like bret said, mold temp and alloy temp are two different things.
for the short fat ones i like to let the alloy run into the mold from an angle.
but the long skinny ones usually like to have some pressure behind them, i shoot them straight into the cavity.
the mold must be warm 375*-425* to be effective, the alloy not so much.
i have cast with alloy temp as low as 615, but generally go with 675-700.

[fredj338]

Steve I often pressure cast for best mold fill out, especially w/ HP molds. On my Magama it's a full speed pour. It seems to drive air out of the mold better & prevents internal voids. Slow pours often leave bases that are not properly formed.

[1Shirt]

Fast and hot, the faster and hotter the better as long as you are doing it safety.
I like a little frosting on my blts.
1Shirt!:coffee:

[MikeS]

Another thing to consider with a bottom pour furnace is the level of the melt. I find that I get the best fill-out with the 20 lb pot, from full to about half full. I attribute this to what I call "head pressure". I also fill as quickly as I can, and keep my temperature from 700 to 800 deg.F. Casting in tandem with two moulds also speeds up the process because you are busy with one mould whilst the sprue is cooling on the other.

There's really no reason to have your pot at 800 deg F unless you're casting pure lead. If your lead has any tin in it, by casting at 800F or higher is wasting the tin. First off it will oxidize out faster, and it also looses it's ability to help the lead flow (and fillout the mould) once it gets more than about 750F. I cast with Lyman #2 alloy (90% lead, 5% tin, 5% antimony) at 650F and it works great for me. The key as somebody else has already said is MOULD temp, not POT temp! When my moulds are nice and hot I can cast lots and lots of boolits that have a nice satiny finish to them, not shiny, not frosty, but something inbetween.

I also find that I get better results when the lead isn't going into the mould too fast. It has to be fast enough that the entire mould fills before any of it starts to harden, but slow enough to be controllable. I find if it's too fast I tend to get lead squirting out of the mould, and getting all over the place. At the proper speed I can leave a nice sprue puddle without having any spilling over the sides of the mould. Of course what works for me might not work for you, so YMMV applies here like it does in most places!

[Shiloh]

Fast and a little tilted. A little extra on the sprue seems to produce the best boolits.

Shiloh

[Colorado4wheel]

A long time ago I settled on pouring fast and hitting the edge of the sprue plate some of the time. I found as long as I poured fast I got good fill out more often then not. I found hitting the side of the sprue plate in different spots avoided hot spots on the mold. I use horrible range scrap lead that I fortify with some better lead. I hate paying for lead so I am stingy on how much of the good stuff I mix in. I found that 725-750F with this mold is fine. Any above that is not helping me and can cause fining with the hotter lead. I was just wondering if perhaps I was missing something.

[Lizard333]

It matters to me how much lead is in the pot. With a full 20 lb pot that lead comes out pretty darn quick. After a few minutes it becomes a little more manageable. I usually take a break when the pot gets down to about thirty percent. By then the pour us getting kinda slow, and I need a break. ;)

[Colorado4wheel]

I stop at 50% full for the same reason. I have preheated lead ready to add into the pot at that time.