Too many cavities for heavy boolits?

[rongaudier]

The saga continues...
First I had my own mold made. Iron block, single cavity 374 gr .452 cal. Boolits came out great, but the ogive did not work in the throat of my rifle so had to reject that.
Went ahead and ordered a 3 cavity, .452 400 grain aluminum block mold from Accurate Molds.
Let the mold warm up...tried casting at temps ranging from 770 all the way up to 900. Getting plenty good flow out the pot. Boolits came out wrinkly and looking like dog ****.
I'm thinking a 3 cavity mold may be to hard to keep up to operating temp with these heavy boolits. What else may be going on?

[rongaudier]

I think I've answered my own question. Another mold for the scrap heap I guess. I don't think I'll be able to keep this one warm enough to NOT get wrinkled boolits. I have run a 6 cavity Lee mold before with no problems, but that was with 158 gr boolits, not 400 gr. I guess the bigger they get the more of a challenge it is to keep everything up to temp.

[ascast]

you have really de-greased them, right? I have found larger boolits heat things up faster. Ladle or bottom spout? You might try pouring lead over the side of the block to warm it up. You might try that for 10-15 casts. Pour over one side, then the other.

[rongaudier]

So you think a 3 cavity of this size isn't too large? You know, I didn't really degrease the mold hate to say. Looked pretty clean when I got it.

[Kitika]

Clean the mold thoroughly and make sure the lead itself is hot enough for a good fill. I cast 500gns .45s in a five cavity yesterday and the only trouble I had was keeping the mold cool enough to solidify the bullets. I was running the pot slightly hotter than normal to stop the wrinkles and after every pour rested the mold on a wet rag to cool it down. Hope that helps you get some good bullets!

[rongaudier]

How hot is too hot? I poured at 900 degrees and no wiping on the sprue plate also no frosty appearance. Still wrinkly. Had to take a break. Thanks.

[waksupi]

Try adding more tin.

[Kitika]

I don't run a temp gauge I just go and start casting and get it working. Degrease the mold preheat the mold in/on the pot and start casting quick until you get full fillout and try and maintain that heat in the mold which should be easy because of the large amount of hot molten lead going into it.
With the bigger molds like my new 500gn I did all of the above but couldn't get rid of the wrinkles until I turned up the lead heat a little.

[OS OK]

So you think a 3 cavity of this size isn't too large? You know, I didn't really degrease the mold hate to say. Looked pretty clean when I got it.

There is part of the problem...you'll have to solve this one before you can worry about the mould temp.

[Harter66]

I have a NOE 454424 aluminum 5 C . It takes about 17-20 pours with a 750° pot on the preheated mould to have it over heated . Even the 6C Lee 452-255 isn't all that hard to get too hot .
I think that a bath in Dawn and hot water will set the mould straight .

[Dan Cash]

I am casting with an Accurate 3 cavity 46-510P mould using a ladle. Afte degreasing the mould, I bring it up to temp by pouring copious quantities of melt in the sprue holes. Once hot, the trick is to keep from over heating. I pour, give 1 minute cooling with the mould sitting on a heat sink, dab the sprue plate on a wet cloth then cut the sprues. This gives me mearly perfect bases and an acceptable rate of production.

Clean your mould and get a ladle.

[JonB_in_Glencoe]

there must be some grease in the mold.

I have a couple large cavity molds, both 3 cavity. One is a Iron Ballisticast 501 385gr RF (for 500 S&W) and the other is a alum NOE 501 550gr RN. Both of these heat up quick and want to easily overheat. I run a small fan to blow over the area where I dump the boolits, and will hold the mold open in that area, so the fan can cool it off some, when the mold is getting too hot. It takes a while, but you will develop a rhythm for how long you need to 'hesitate' holding the mold in the fan breeze.

btw, when I ordered the Ballisticast, it was strongly suggested I go with 4 cavity blocks, but with 3 cavities, for a mold with large cavities...more mass makes for more consistent heat, meaning that minimizes the fast temp swings.

[country gent]

I would clean the mould good. first with acetone brake cleaner or thinner and a tooth brush. scrub it really good. Then hot water and dish soap with the tooth brush and really work up a lather. rinse under running hot water. If there are vent lines with a awl, scribe, or bamboo skewers point make sure vent lines are clear and open. Warm mould on top of pot or in a mould oven while pot comes up to temp. I would start out with a lead temp of 750* and work from there.

[John Boy]

First a clean mold, then
* heat the melt & mold to a temperature so the sprue puddle frosts in 5 to 8 seconds
* Then, pour each mold cavity with a full ladle with a 5 second pour

[runfiverun]

put your alloy temp back down.
more like 700 is all you need 725 maybe if your loafing along.
all that lead your putting in the cavity's is heat, keeping the mold up to temp should be no problem.

you just need to get all the cutting oil out of the mold.
then run a couple of short sessions and allow the mold to cool back down in between.
you can do this by pouring about 20 pours into the mold then setting it off to the side to cool then warming it up again and doing another short run.

you'll see the boolits start getting good during one of the short runs.
that's when you just go ahead and make a pile of them.

[longbow]

I'll go with more heat. Pre-heat the mould until the sprue plate lube just starts to smoke and you will have the mould just a bit hotter than it should be but it will settle in after a few pours. At first the sprue puddle will stay molten a bit long so just wait a few seconds.

Most clean the heck out of new moulds to get them to cast but I don't bother much. I think pre-heating the mould to just under the melting point of the lead is the secret... works for me anyway. Nothing wrong with cleaning the mould though. Use brake cleaner, mineral spirits or scrub with Dawn dishwashing soap and a toothbrush. All will work.

I have not used an Accurate aluminum mould but have cast with two Accurate brass moulds and both behaved the same... they like to be run hot and fast to keep the mould up to temperature. Start casting and keep going at a steady and fast pace. Don't stop to look at each boolit. I suspect the Accurate aluminum mould acts much like the NOE's ~ pre-heat and cast fast and steady.

Even the thought of scrapping an Accurate mould makes me cringe! Tom wouldn't make it if it wouldn't work. That and the large boolits certainly will keep that mould hot enough. If you think it is a bad mould then I am sure there are many here who will pay the shipping to take it off your hands.

As for temperature, well, I can't be very precise there as I do not use a thermometer. I learned to cast "by eye" looking at the surface and colour of the alloy to judge when it is the right temperature. What I do know is that I have to turn up the heat and make sure I keep up a quick steady cadence with brass moulds and NOE aluminum moulds. If I am not casting fast enough that I wind up waiting for the sprue puddle to harden then the alloy and/or mould is not hot enough.

I find more heat usually helps fill out. Also, fluxing and drossing regularly helps bunches.

Waksupi's suggestion of more tin is a good one too. Adding some 50/50 bar solder certainly won't hurt and will make the alloy more fluid giving better fill out.

Try again with more heat, maybe some added tin and cast fast and steady. I am confident the mould, boolit size or number of cavities is not the problem.

Longbow

[mold maker]

Pour melt generously into a cleaned HOT mold until you get frosting. That means pouring and dumping fast without inspecting the product. Then reduce the frosting by, 1. cooler melt, 2. slower pace, 3. using a damp rag. You likely created your problem by skipping the mould cleaning.
The larger the boolit the more heat your introducing into the mold, not the other way around. As others have said, think of it as pouring heat, not lead.
Aluminum molds absorb and transfer heat faster than the other mold materials, so the pace will need to be somewhat altered. Use mold lube VERY SPARINGLY as in a slightly damp Qtip, and wipe any wet spots off with a dry Qtip. The correct amount can barely be seen.
Just keep at it and success will be the reward.

[rongaudier]

I just finished my session after giving a good clean. I ended up with about half rejects, but enough that are good enough to go ahead and powder coat. It does seem like they did better once the mold got up to temp. I might try the ladle method. Gotta get a ladle first. Thanks for the input and I'll post pics later.

[reddog81]

I always thought larger grain molds were much easier to heat up. If anything I have to use a slower casting pace to keep them from over heating. Little 32 ACP molds have the opposite problem. They take much longer to heat up and you must keep the casting pace fast otherwise the mold cools off.

[Oklahoma Rebel]

the larger cavities mean it will heat up faster, because there is less mass in the mold blocks to heat up, but it also means it will not hold heat as long. so as long as you have a good rhythm going it should stay hot, even get too hot like some said

[BigMagShooter]

cast with it a session or two more, I suspect oil in the cavity to cause wrinkly bullets.

let the mould set on top of the pot as it's heating up, that will help get rid of the impurities and help it.

[plainsman456]

You might try just casting several times.
It might need some breaking in/seasoning.

[rongaudier]

I'm not sure what the issue is, but I managed to get enough done to go forward with my testing. Initial results are better than with my old boolit as it will now go into battery, and I can get it back out of battery as well as the ogive of the boolit is no longer jamming into the throat. Another side benefit is I'm not blowing out primers and showing other scary signs of over pressure like I was before.
I'll keep working with this mold. Maybe it's a combination of technique and just breaking it in.

193914193915

[mozeppa]

like was already mentioned.....add more tin.

that is a lot of area to fill...tin is your friend.

a clean mold.
get a $13 oester hot plate....turn it all the way up and set your mold right on it.

i have a thermometer on mine and it tops out at 450 then work a rhythm of casting.

you'll find it will work.

oh....and keep the alloy around 720 or less .

[rongaudier]

where is a good source of tin, and how much should I use. My base material is range scrap.

[TexasGrunt]

With a new NOE aluminum mold you are instructed to first clean the mold using hot water, dish soap and a toothbrush. Then heat cycle the mold at least three times. This means get it up to casting temp and let it cool, repeat.

Once that's done give it a light smoke with a butane lighter.

I followed those directions and was casting perfect boolits in a hollow point mold within four pours.

Your errors were not cleaning and heat cycling the mold. Also try smoking the mold.

You can find tin at Rotometals.

With all honesty it really sounds like to you need to start at square one. I highly suggest sitting down and reading this. http://www.lasc.us/fryxell_book_contents.htm

[rongaudier]

I did clean with soap and water very thoroughly before my last session and used a toothbrush. I did not do the heat-cycle thing. I also did not smoke the mold this time (as I have in the past) as I have heard from various sources that this is not necessary. I'm not having issues getting the boolits to release. I think what may be happening is I'm not getting good enough or fast enough flow into the mold. I did try and run an allen key up the hole and it did seem to help. Some have suggested using a ladle which I may try if I can't get this pot to work right. Really haven't had this much bad luck with my other molds.

[gwpercle]

With those large boolits you want to fill the cavities fast, try ladle casting. Get one that has a side spout and holds at least twice as much alloy as one boolit. Make sure the ladle spout hole is as large as the sprue plate hole.
Keep the ladle in the pot full of hot alloy . Fill the ladle , press the spout to the sprue hole and invert, Fill and leave a generous sprue . Repeat for the next two cavities.

The machining oils in aluminum go deep into the pores , heating the mould drives more to the surface. I've found acetone to be effective , soaking in it , tooth brush scrubbing with it and after the second or third session all the oil has surfaced and been removed. The mould looks clean because the oil is not on the surface, but the heat brings it up. Third casting session is the charm.
Gary

[rongaudier]

Yea the boolits were definitely getting better towards the end of the session. We'll see how session 3 goes.

[TexasGrunt]

Smoking the mold does a lot more than helping with release.

[rongaudier]

Yea well I guess don't hurt to try it, have done it in the past. At this point though I'm 99 percent sure the issue in this particular situation is the pour rate and and/or getting better with my technique.
I've done thousands of .358 and .308 bullets and never had this particular problem past the first 10-15 boolits. This is my first big boolit experience with a multi-cavity mold.

[jethunter]

The saga continues...
First I had my own mold made. Iron block, single cavity 374 gr .452 cal. Boolits came out great, but the ogive did not work in the throat of my rifle so had to reject that.
Went ahead and ordered a 3 cavity, .452 400 grain aluminum block mold from Accurate Molds.
Let the mold warm up...tried casting at temps ranging from 770 all the way up to 900. Getting plenty good flow out the pot. Boolits came out wrinkly and looking like dog ****.
I'm thinking a 3 cavity mold may be to hard to keep up to operating temp with these heavy boolits. What else may be going on?

I don't think it's the mold design. Generally speaking, bgger cavities = more hot alloy = more heat to the mold. Usually the issue with big bullets is cooling the mold, not getting it hotter.

Wrinkly boolits are probably low mold temp or contamination. Scrub the mold with boiling water, dish soap, and a tooth brush, then rinse in clean boiling water. Preheat the mold if you can. Once you start casting, keep a rhythm going and don't stop to look at the product, keep going. Stopping allows mold temperature to fall off again. Pour, allow sprue to harden, dump, repeat, and keep going.

Most casting problems are due to low mold temps in my experience. Don't be afraid to start off with the pot a bit hotter, you can turn it down after the mold starts working.

[fredj338]

So you think a 3 cavity of this size isn't too large? You know, I didn't really degrease the mold hate to say. Looked pretty clean when I got it.

There will likely be cutting fluid still in the mold so cleaning them is the way to go. I also find the molds sort of break in or just cast better bullets after a few 100. I have several molds from accurate & they all do better now than when new, probably because I didn't get all the cutting fluid off them. I get good results with 6cav Lee mold sin 45 & IMO the alloy in the Accurate molds is better.

[bluejay75]

I use a 75/25 mix of concentrated dish soap and simple green. I clean the mold for the first few uses. By then whatever magic happens in the molds happens and it's no longer needed.

[Harter66]

I bought a brand new Mountain Moulds custom a quick bath in Dawn and hot water and 3-4 heat cycles over desert and later morning coffee and it poured perfect bullets preheated while the pot came up to temperature on the 2nd pour .
I bought a 7mm 150 gr NOE washed it 2-3 times did the as instructed heat cycles and over 4 yr cast it probably 12-15 times 100-200 keepers and 35-70 pours, the last time I poured it I got 25 straight pours out of 29 with 4 bullets that were all good . I don't know if I just finally worried it into submission or something in my set up or technique changed but I can't count the number of pours that had 2 wrinkled bullets in the 2 hot cavities that just cast keepers .

Stuff happens and sometimes there's no tangible reason you just have to do the steps over in case you missed something .

[jethunter]

[
I bought a brand new Mountain Moulds custom a quick bath in Dawn and hot water and 3-4 heat cycles over desert and later morning coffee and it poured perfect bullets preheated while the pot came up to temperature on the 2nd pour .
I bought a 7mm 150 gr NOE washed it 2-3 times did the as instructed heat cycles and over 4 yr cast it probably 12-15 times 100-200 keepers and 35-70 pours, the last time I poured it I got 25 straight pours out of 29 with 4 bullets that were all good . I don't know if I just finally worried it into submission or something in my set up or technique changed but I can't count the number of pours that had 2 wrinkled bullets in the 2 hot cavities that just cast keepers .

Stuff happens and sometimes there's no tangible reason you just have to do the steps over in case you missed something .

When you start getting that cavity that keeps dropping poor bullets and you are ladling - reverse your pour - if you usually start from the back cavity, start in the front instead, and vice versa. As often as not the problem cavity starts to work and I have to think it is temperature related.

[Harter66]

Jet
I poured it six ways from Sunday . I haven't had a problem with the other 9 , not even the 5C 22 cal but that one ......... an exercise in patience to be sure .

[44man]

I have a huge drawer full of molds, all I bought and all I made myself. I have to 564 gr molds. All I ever done was dish soap and hot tap water even when I used WD-40 for cutting lube.
I made the little electric box oven for the hot plate and put a BBQ thermometer in top. I soak at 500° and set the Lee pot at 750. 800 for pure lead. I never get a reject. I ladle pour. I have run 3-2 cavity molds at once. I never mastered the bottom pour.
The hardest job ever is to teach how to cast. I don't know anyone that "gets" it.

[Wayne Smith]

i came to the conclusion years ago that EVERY mold is a learning experience and has something to teach me. The question is - am I willling to learn?

[Beau Cassidy]

I once had (and still have) a Ballisticast .458 mold. When I first got it I cast a few times with it using bottom pour and it did fine. The third time I used it I spent about 2 hrs trying to get bullets to fill out. I remembered I had a Lyman mold somewhere so I dug it out. The FIRST pour with the ladle gave the most beautiful bullets you have ever seen.

Moral of the story is for large bullets use a ladle. It will save you a little stress.

Oh- another thing that will probably blow a few people's gaskets- I have NEVER cleaned a new or old mold to get oil off in 30 years of casting. I just fire up the pot and start pouring. Hot lead burns off any existing oil.

[rongaudier]

Well I've done a little shooting with the 400 grainer and it is not quite up to snuff either. Having issues with the meplat interfering with some part of the barrel extension. I got an improved design on the way. This time I ordered in 2 cavity only. Should be a little easier to run. Here is my new design in the Accurate Molds catalog.
Sooo, ran the calculations, and I think if I can get this baby up to 2000 FPS that's 3300 lb ft at the muzzle!

194600

[44man]

I change lead now and then in my pot, I just wear thick gloves and hold the rails to pour into an ingot mold. No matter what I use or how much I flux, there is that black ash looking junk in the bottom, why it does not float is a mystery. It must be uranium!!!
Anyway I was always poking the junk out of the spout. Flow would change after a few casts. Heat rises and there are no elements in the bottom so I assume the spout is cooler. I tried and tried until I made a tapered brass plug to fit and removed the rest of the stuff from the pot so a ladle fit better.
I bought the lee BP because they were out of stock with the production pot. I never got the Lyman or RCBS pots to work either.
I went back to what I know from almost 67 years of fooling with casting something from the prettiest sinkers to fishing jigs. Boolits were SOOO much easier. Better molds.
Back then they did not know mercury was poison, we rubbed it on silver dollars with our fingers to shine them, drop a drop on the floor and it ran little drops in between the floor boards.
Today they would wrap the house in plastic and condemn it. :D
Years of handling sinkers might have made me the gun nut I am. We survived.

[rongaudier]

I haven't cleaned out my pot ever. I bet the bottom is pretty cruddy. I've been running a small allen wrench up the hole to clear it out. I think I'll go ahead and do like you say, dump it and make sure there is not crud on the bottom. Yea, I think it's a flow issue.

[rongaudier]

Well I cleaned out my pot and yes, there was tons of that brown crud in there. The hole was pretty well plugged too. Got that all cleaned out now, I'm expecting good flow.
What got me thinking more along the lines of flow was when I was watching old Fortune Cookie at work and noticed his pot was flowing much better than mine. I guess I got away with it for
a long time casting only little boolits. We'll see how it goes now.

[44man]

Well I cleaned out my pot and yes, there was tons of that brown crud in there. The hole was pretty well plugged too. Got that all cleaned out now, I'm expecting good flow.
What got me thinking more along the lines of flow was when I was watching old Fortune Cookie at work and noticed his pot was flowing much better than mine. I guess I got away with it for
a long time casting only little boolits. We'll see how it goes now.
I am stupid and do not know how the junk does not rise to the top. Lead is heavy so it makes no sense. But I am happy you seen it. But it will return.

[rongaudier]

Well it was like 5-6 years of accumulation. I'll make sure to clean the pot more often. Probably got more than half a cup of that stuff out of there.

[OS OK]

Sometimes we chase our tails trying to fix a problem that hasn't been properly identified. "Ask me about hard ingots!" . . . :bigsmyl2:

These 4 on the left have 'gas' problems...from oil or something in the mould that didn't get cleaned out. Those indentations don't have hard edges around the imperfections. They look like the mould is raised in that area because the Pb is seamless all around the divot, (gassing bubble) and in some cases, if it is a long smear of oil (or whatever) it will run up or across in an irregular shape...but the edges look seamless. It will keep showing up in the same area of the same mould cavity from cast to cast. The first, third and fourth from the left I believe came from the same cavity.


194628
The casts on the right show 'temperature' problems and hard edges from where the Pb hit that area of the mould and froze and as the cavity filled the Pb came to the edges of the frozen metal and joined up tight showing the hard edges.

I think sometimes when the mould is running 'borderline' hot enough, if we don't get the Pb in the center of the sprue hole it will ricochet off the sprue and loose heat there and when it hits the side of the cavity it freezes. That's why I try hard to hit the center of that sprue with the bottom pour pot and run that stream as fast as the pot will deliver.

I wish I had better examples to show but those end up in the pot again.

[rongaudier]

Most of mine came out looking like the ones on the right.

[OS OK]

With a new mold you don't know what to expect, then molds of different materials have their own requirements too as far as temp. and casting tempo, but I think? that if we work out the temp. problem first these subtle gassing irregularities will show up second. When the casts look like the ones on the right, it's hard to tell if the mould is gassing too.

I think I learn the most about our hobby when I have to figure a problem out. Especially so when you bring your problems to this forum seeking help in solving the mystery.

[rongaudier]

Yea I'm 99% sure it was a flow problem. I'll find out with my next casting session.

[deadeye ruck]

I cast a lot of bigger bullets between 400-550 grains. I have a couple of 6 gang 50 cal moulds. The trick we have found is to ladle pour them and run the pot around 850. I use a propane burner (deep fryer) to preheat the mould to get it good and hot. I also have an RCBS bottom pour but getting good bullets is a chore with it.

[rongaudier]

And the winner is....44man.

Yup it was all the junk that had accumulated in my pot over the years that caused the problem. Now getting great flow and casting beautiful boolits.
Thanks

[fredj338]

I just finished my session after giving a good clean. I ended up with about half rejects, but enough that are good enough to go ahead and powder coat. It does seem like they did better once the mold got up to temp. I might try the ladle method. Gotta get a ladle first. Thanks for the input and I'll post pics later.

If using a BP pot, trying pressure casting; holding the spout to the spru plate hole for the entire pour & lifting it up to form the spru at the end. It isn't the 3cav/45. I get good results with 6cav 45/230 in the cheap Lee alum molds.

[Tenbender]

I have a 5 cav. NOE 180gr. mold for my 357 Max. I have to heat it and pour at 750 and it still takes a long time to get enough temp. in it. Once it gets hot it makes beautiful boolits.