Trying New Accurate Mold

[don45]

I just got my new 45 Auto mold from Tom at Accurate Molds. It's a beauty but for some reason I'm having trouble getting good bullets to come out.
Although most of the time I think I know almost nothing about this business, I have been casting bullets for 50 years and have cast 10's of thousands of 30, 38, 44 and 45s.
I have especially cast and shot tons of 45 autos, mostly Lyman 452488. I'll add a post with more info about this mold which is still my main 45 auto mold.

A few days ago I tried to cast with the new mold for the first time, the Accurate 452-230M. I used my RCBS furnace but couldn't locate my thermometer. I felt the lead temperature was too low and the spout kept freezing on the mold. About half of the bullets cast were wrinkled, not completely filled, especially around the base. It seemed that the far cavity never produced a good bullet and the other two were hit-miss.

Today I switched to my old Saeco furnace which has been my stand-by for 40 years or so. I located my thermometer and set the temp at about 710 which is where I've had great success with my Lyman 4-cavaties (44, 30 and 45). The Lyman mold produces almost perfect bullets for the first pour into a completely cold mold. I heated the Accurate for some time and got it up to temp with continuous casting.

One thing I know from past experience, and confirmed again today, is that the Lyman likes a 'certain' flow otherwise it leaves an air hole in the base of the bullet. This happens when the lead flow is too fast and the air can't escape (my theory). I set the flow using the adjustment screw on the Saeco to where the flow is a dribble, and then slowly increase until it is just a steady stream. This works great and is how I adjusted it today. The Lyman 452488 (185gr) worked fine with this but the Accurate would not properly fill. It looks like a little lead hardened and then more poured on top. I increased the flow some and it seemed to help, perhaps because it's a 230gr bullet and therefore needs more metal faster.

At first most of the Accurate bullets are filled with air pock holes, see photo. By increasing the temp and flow the pock holes seem to go away but I still get wrinkles on most of the bullets.

Today I used Lyman #2 alloy, the other day I used pure WW, which is what I usually use for 45 Auto.

This is my first experience with a Brass mold. In fact, almost all of my molds are old Lymans. I probably have 50 molds total and almost all are Lyman. I have a new RCBS 44 350K two cavity which works great and a couple of Saeco molds as well.

I shot a bunch of the Accurates in my Colt Commander the other day and they feed well as expected. I like the design and hope I can work out the kinks. I'm certain it is not a problem with the mold but just something I'm doing wrong. I've only had two casting sessions, but thought you all might have some tips which will help me get this going.

Thanks in advance.
Don

Accurate AM452230M:
http://castboolits.gunloads.com/imagehosting/thum_36454e7d32e01b95a.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=2205)

Problem Boolits:
http://castboolits.gunloads.com/imagehosting/thum_36454e7d332f640cf.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=2206)

[ss40_70]

i have zero expeariance with brass molds and hopefully some who does helps you , but what i have read is that brass molds like to be run a good bit hotter than iron, could be just turning the heat up a bit will fix things right up

[don45]

Here's my favorite mold of all time, the Lyman 452488.
I bought this mold used about 40 years ago. It looked exactly the same then, and I didn't even want it when I saw it. They guy I bought if from claimed it was the best mold and that I could return it if I didn't like it. It simply is the best. I have never understood how / why the cavities look the way they do. They look rusted but are not. I don't know how they became like that. I have always stored it dry, usually with bullets in it. Since I live in the very damp NE I store all my molds in dry boxes with large drying bags. The molds are left just as I finished casting and the dry bags keep them from rusting. I've been here for 30 years and it's always worked.

There's not much you can do to make this guy cast bad bullets!
I know I've cast at least 20,000 bullets with this very mold, probably a lot more!

If I could figure out how to make my other molds like this one I'd do it in a second. For example, today I cast the four bullets shown here with the mold completely cold. These are from that first cast. I cast about 200 bullets with this guy and other than these four, only one was bad.
If you look closely the third from left has the nose not completely filled.

Lyman 452488:
http://castboolits.gunloads.com/imagehosting/thum_36454e7d3570debc6.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=2207)

The first four bullets cast today from a cold mold:

http://castboolits.gunloads.com/imagehosting/thum_36454e7d35a4ac19a.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=2208)

And some more:
http://castboolits.gunloads.com/imagehosting/thum_36454e7d35c5f2213.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=2209)

[white eagle]

some times it takes a few sessions to get a mold to
cast good boolits
I am having the same issues as you with a brass from MP molds
its this seasoning that once complete boolits start falling like rain
give it time Tom's Molds are first rate

[don45]

Seasoning does make sense. Just look at the 'seasoning' on the old Lyman!
It's just so great looking and I love the bullet design I just want to get a bunch of these to shoot!

Thanks!

[Dennis Eugene]

Blew the pic up some and to me it almost looks like oil in Cavities. Probley a dumb question but did you clean it good? Dennis

[don45]

Not a dumb question...I seldom oil the molds I use regularly so just grab them and cast.
I inspected this one, cleaned the cavity with a cotton swab and blew it out with compressed air.
I never used alcohol or break cleaner which I use on an oiled mold.
I'll sure give it good cleaning, that may be it.
Did you see oil on the mold picture or deduce that from the looks of the bullets?

[geargnasher]

Blew the pic up some and to me it almost looks like oil in Cavities. Probley a dumb question but did you clean it good? Dennis

My first thought as well. Oil bubbling out of the pores.

Here's the dope on Tom's moulds according to me, which is free advice and worth exactly what you pay for it: Free-machining brass alloy varies greatly in specific heat depending on exact composition, but it has a far higher coefficient of heat than aluminum, which is higher than iron. That means it needs to be hot to begin with, and it loses heat quickly. If you aren't casting at least three full cycles a minute consistently with your alloy at 710, you won't get or keep it hot enough for good fillout.

Here's a similar boolit, one I had Tom design to my specs (45-230L), and it's exactly 230 grains as I asked, cast from clip-on wheel weights + 2% tin, alloy about 675 degrees, cast at a rate of three-four pours per minute, mould preheated to 450 in my mould oven:

http://castboolits.gunloads.com/attachment.php?attachmentid=28901&d=1296091775

Here's the oven:

http://castboolits.gunloads.com/imagehosting/thum_89094e5ad65ae2e31.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=1966)

It looks to me like you need to get the mould hotter, cleaner, and cast faster.

Gear

[white eagle]

also brass sometimes like to be hot
to start then back to norm,

[geargnasher]

Not a dumb question...I seldom oil the molds I use regularly so just grab them and cast.
I inspected this one, cleaned the cavity with a cotton swab and blew it out with compressed air.
I never used alcohol or break cleaner which I use on an oiled mold.
I'll sure give it good cleaning, that may be it.
Did you see oil on the mold picture or deduce that from the looks of the bullets?

Going by the look of the boolits in your picture.

Scrub the mould cavities with hot water and Dawn or similar, when you think they're clean, do it again. A trip through the dishwasher with the sprue plate and handles removed is also really good way to leach out the machining oil in the pores of the metal.

Give it another go, you'll probably have to "overhaul" your familiar casting routine to get good boolits out of these fine, heavy, brass works of art, but once you get the algorithm figured out, I'm sure you'll like it.

Gear

[don45]

I think you guys really nailed it, and fast.
I can't wait to give this another shot after I clean it well and work on getting it hotter.
Gear, tell me more about your mold oven. I've always struggled with getting the molds up to temp but have just always cast a bunch of bad bullets. Usually just a few, but for some molds it's more of a problem. The oven sounds like a perfect solution.

[geargnasher]

My mould oven is an idea I stole from member Montana Charlie, he "invented" it as far as I know and posted a pic of his here once.

I had an old electrical work box and cover laying around that had no knock-outs or screw holes in it, so I cut out a hole in the side with my plasma torch and drilled a hole in the top for an outdoor grill thermometer purchased at Home Depot. It sits on an 1100-watt, open-coil hotplate. I keep the hotplate thermostat set nearly on full, which gets the air inside the oven about 450 degrees. I keep it going during a casting session so that the mould can be parked in there any time I need a break, even for a few seconds and it stays at casting temperature. I can't imagine useing a Lee or NOE six-cavity aluminum mould, brass Mihec or Accurate mould without it.

It takes about 15 minutes to get the whole mould heat-soaked once placed in the pre-heated oven, so I stick it in there and turn it on when I turn on the lead pot. They get ready at about the same time.

Gear

[longbow]

Here's another vote for more heat and pre-heating the mould.

I find my brass moulds like to be run fast to keep the temperature up. I cast fast and steady to keep them going and they work well.

I have three brass moulds ~ two Mihec and one Accurate. I usually pre-heat until the sprue plate lube starts to smoke a bit and that does it for me. Once going I keep casting at a "brisk" pace and adjust lead temperature so that the sprue puddle takes a few seconds to freeze.

Not very scientific but it works for me and all three brass moulds cast beautiful boolits.

Longbow

[cajun shooter]

It has been my findings that using a large single burner hot plate to preheat the brass moulds works very well for me. I will go along with gear and others who posted this. My hot plate is turned on to max with both moulds on top at the same time that I start my Pro Melt.
I have found that by using the two mould method with the brass moulds works as well or better than when doing the same with the iron moulds.
I have purchased moulds from Tom for over a year now and advised others to do the same and have yet to throw a single bullet away.

[44man]

I would just love to have a few of those beautiful molds.
I use the mold oven too and the first boolits are perfect but I take my large aluminum molds to 500*.
I am goofy with bottom pour stuff and have never made good boolits with any of them, too many problems for me. My first BP was in 1953 and I gave up fast, went to a ladle and will never go back. I have plugged all those holes with a tapered brass pin from inside. :bigsmyl2:
I cast at about 750* all the time and go to 800* for pure. Quality is controlled by casting tempo, there is no hurry to make perfect boolits.

[FN in MT]

Don45,

Don't feel alone. I've been casting since high school in the 60's. Only way I could afford to shoot. I bought my first brass MIHA mould a few months back. And after casting a few hundred thousand slugs from iron moulds...it was like starting over.

I had to turn my heat way UP and as I often cast in a 50 degree garage in cooler weather...got a one burner hot plate to keep the blocks warm.

I guess Old Dogs are going to need to learn new tricks! LOL.

FN in MT

[longbow]

I'm with 44man on ladle casting too. I find ladle casting easier so have done it that way for about 40 years.

[white eagle]

yeah some times the old techniques used need to be modified somewhat
to get good boolits
not only every gun is a law unto itself but it would appear every mold as well
best of luck

[geargnasher]

True, most moulds have quite unique preferences. The other monkey wrenches in the works are the variations in alloy and weather. I used to keep a casting log, documenting ambient temperature and humidity, alloy approximation, pot temperature, mould temperature, casting pace, flow setting, mould rest height, flux technique, etc. but this was really only during the steepest part of my learning curve. Once I figured out that each casting session was unique, I began to a see a pattern with what worked best with typical ternary boolit alloy:

Preheat mould in oven.

Get alloy to 100 degrees above full-liquidus point, flux, skim, and stabilize the temperature there.

Begin casting. Use clues such as the time it takes for the sprue to set, the "finish" or surface appearance of the boolits, tendency of base voids to form, and a bunch of other minute details to determine what needs to be altered. Casting rhythm, stream size (bottom pour), stream distance, swirl angle, sprue puddle size, timing of sprue cut, mould opening/closing/refilling, etc. all are little tweaks I make to get the mould temperature and fill rate "in the Zone". Once I get it there, I keep it there. Next session will be different, even with the same mould, so no point in writing it down.

This process is automatic for me now, so it's easier to use these simple guidelines and techniques to get the feel of each session rather than referencing a set of instructions that may or may not work for the next session.

Gear

[ColColt]

I have one of Tom's mold for the 44 and all I did was take a Q-tip with alcohol on it and wipe out each of the halves of the mold(2-holer), put on my hot plate set at medium and by the time the alloy was liquid I started casting. After a couple times it started casting like a well seasoned cast iron mold. I had 4-6 rejects at first but that was it. Temperature of the alloy ran from 675-700 for 260 gr boolits.

http://i180.photobucket.com/albums/x220/ColColt/Misc%20Stuff/_DEF4151a.jpg

[max it]

My first thought as well. Oil bubbling out of the pores.

Here's the dope on Tom's moulds according to me, which is free advice and worth exactly what you pay for it: Free-machining brass alloy varies greatly in specific heat depending on exact composition, but it has a far higher coefficient of heat than aluminum, which is higher than iron. That means it needs to be hot to begin with, and it loses heat quickly. If you aren't casting at least three full cycles a minute consistently with your alloy at 710, you won't get or keep it hot enough for good fillout.

Here's a similar boolit, one I had Tom design to my specs (45-230L), and it's exactly 230 grains as I asked, cast from clip-on wheel weights + 2% tin, alloy about 675 degrees, cast at a rate of three-four pours per minute, mould preheated to 450 in my mould oven:

http://castboolits.gunloads.com/attachment.php?attachmentid=28901&d=1296091775

Here's the oven:

http://castboolits.gunloads.com/imagehosting/thum_89094e5ad65ae2e31.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=1966)

It looks to me like you need to get the mould hotter, cleaner, and cast faster.

Gear

HI Ya Gear,
It looks good to me too, I have a garage full of 4" square electrical boxes. And a hot plate. My new acquisition, a Lyman 452460 = 4 banger, keeps getting wrinkles. I will try hotter mold next time.
Much obliged,

Max

[don45]

Thanks for all the tips and suggestions.
I'm going to give it a good cleaning, get a hotplate to preheat, and run the alloy temp up some.
Sounds like that should get me going.

I have a Waage Electric pot and have used it to ladle cast a few years ago. I started out for many years using the little Lyman pot on a gas burner. In those days I only had single cavity molds and the Lyman ladel with the roll to fill motion worked great. Eventually I got the bottom-pour Saeco furnace and have had great luck with 4 cavity molds. The 452488 mold just doesn't care how it gets the lead and always dumps excellent bullets. I wound up with the RCBS Pro Furnace and the Waage pot but usually use the Saeco. It has a heavy cast iron pot and maintains constant temp very well. I also like the way the spout pours.

Per your suggestions I'm going to crank up the Waage and try the ladle method with the Accurate mold. How do you, longbow & 44man, do this? What ladle? Do you roll-pour? How much sprue lead?

[reload68]

I had just the opposite problem with one of Tom's brass 45 mold. After the mold heated up I could not help but cast frosted boolits. After my 5th cast, and a thorough cleaning of the mold, I've found that I have to slow down to get shiney boolits. My thermometer says I'm between 650-700 so it's true, every mold is a unique piece of hardware. All I use is WW so I guess you just need to give it a few casts and go from there. If I try to cast at a lower temp my alloy will cool in the spout. Good luck, Accurate molds throw great boolits.

David

[josper]

I also like using a hot plate to preheat my mould.I have an old west mould 459-350 and it needs to be run hot.My results are the same as reload68 and I use the same temps.I like the idea of the oven and I'm going to have to make one.

[GLL]

Tom's molds do come to you with machining oil ! Like Gear I wash mine in Dawn...three cycles with toothbrush and VERY hot water followed by two rinses with acetone.

Super clean + hot mold + Waage pot + ladle = perfect bullets ! :) :)

Jerry

http://www.fototime.com/8F95495D13D5995/orig.jpg

[williamwaco]

Blew the pic up some and to me it almost looks like oil in Cavities. Probley a dumb question but did you clean it good? Dennis




+1 on this opinion.Scrub it with 409 and hot water, several times.

[geargnasher]

Don45, I'd advise against getting crazy with the alloy temperature. Boolit quality is determined by mould temperature, NOT alloy temperature. If your alloy will pour, it will cast. If you overheat your alloy (anything over 750 degrees), you render the oxide-barrier of tin instantly ineffective and drastically increase the rate at which tin oxidizes out at the surface of the melt. If you ladle-cast, it is especially important not to overheat the alloy since you're exposing so much of it to the air each time you dip and pour.

I wouldn't give up on the bottom-pour just yet, especially if you aren't used to ladling. Much easier to keep up the casting pace and keep the mould nice and hot with a bottom-pour, but ladling makes it easier to get perfect fillout. I recommend a Lyman or similar small Rowell ladle, roll-pour with firm contact, then pull away and build a sprue about twice the volume of the sprue well to impart heat to the sprue plate and help make the boolit base edge sharp.

Gear