Order of fill - gang moulds

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Last Post 18 March 2021

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Glenn R. Latham posted this 20 February 2021

I just got a new 5-cavity aluminum mould for a "fat" 314299. Cleaned and broke it in according to the directions, then proceeded to cast. I'm sorry I can't tell you what the alloy was. I'm about out of wheel weights, so I have been using some odds & ends that I picked up over the years. Some ingots were marked "WW & Lino", some "WW & solder", etc. As a comparison, a 45 SWC that weighed 205 grains out of 50-50 WW & lead weighs 199 out of this mix.

Anyway I was casting along and was getting a lot of rounded bands, especially in the middle cavities. I thought the venting looked "minimal", but some antique moulds work fine with smooth surfaces. As a test, I decided to fill the middle cavity first, and work my way out, instead of my usual from one end to the other. Bullet quality immediately improved. Anyone else experience this?

Glenn

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OU812 posted this 20 February 2021

I bet you are using a bottom pour pot. Yes I have experienced your problem with bottom pour and I did fill middle or problem cavities first...yes it did fix problem.

Ladle will fill better, but you have to rotate ladle very quick to prevent partially filling adjoining cavity. It can be done with ladle.

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Qc Pistolero posted this 20 February 2021

Each mould,like guns has its preference.I too met with this or other kind of problem.Getting me a thermometer helped me find the solution quickly to most problems.Some moulds like it at 750*F while others will perform better at 710*F.If I now had to cast without it I'd feel like driving a car without a speedometer.

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Glenn R. Latham posted this 20 February 2021

OU812, yes I am bottom pouring. The only ladle method I've used that worked well (and it works very well for me) is with the ladle up against the sprue plate, then rotate up. First time I tried this with a multi-cavity mould I poured half the lead out of the first cavity when I rotated it over to put the ladle up to the second cavity - oops. Anyway this would be pretty slow, although I may have to give it a try.

Glenn

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OU812 posted this 20 February 2021

Sometimes too much heat can cause rounded Frosted edges. Casting too fast creates too hot mold temp. You can turn down pot temp down to 650 to prevent . My new RCBS with built in digital temp control is the best.

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OU812 posted this 20 February 2021

Yea put the ladle against sprue plate cavity, fill cavity, then rotate ladle clockwise very quickly with wrist to prevent over spill.

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OU812 posted this 20 February 2021

I break open sprue plate with gloved hand. This allows me to cut sprue flatter to bullets base. Those 5 cavity molds can be very difficult to open with gloved hand...so I seldom use them.

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OU812 posted this 21 February 2021

If it were me, I would fill just the first, third, fifth cavity. The mold will vent better and allow easier opening of sprue plate. Mold will also run cooler and not over heat.

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Bud Hyett posted this 21 February 2021

I've got several four-cavity molds and have experimented with the order of fill. The center fill to outside works better for uniformity. I have a three cavity Ohaus mold that I fill center, front, back. The spacing is so narrow that I have to move quickly to prevent spillover to the front cavity.

The other item that helps is to fill as level as possible. One four-cavity is brass and tires me easily. I find myself tilting it back toward me and that complicates the fill.

Farm boy from Illinois, living in the magical Pacific Northwest

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Pentz posted this 21 February 2021

I've given up on gang molds for +/- 0.5 gr consistentcy, they reside unused in my drawer. Fine for handgun blasting, and perhaps the Garand but otherwise wanting for match use.

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BigMan54 posted this 21 February 2021

I have a N.O.E. 5cav for a clone of the #452423. I've been using 50/50 - COWW / #2, a bit hard but it works for me.

I use a bottom pour; old RCBS Pro-Melt with a N.O.E. mold shelf. The shelf has a slight rearward down angle. Alloy temp is about 720degrees. I cast front to back with a generous sprue. I use a 2nd aluminum mold of N.O.E. or Accurate 4cav or 5cav manufacture.

I fill and drop as fast as practical, using a plastic mallet to bust open the sprue plate. And I take the time to close the molds carefully.

Never have lead smear across the tops of the molds. Used the same method with Lyman 4cav molds and the old Mag-20 w/ mold shelf.

Works for me.

And a pair of Lee 6cavs too.

Long time Caster/Reloader, Getting back into it after almost 10yrs. Life Member NRA 40+yrs, Life S.A.S.S. #375. Does this mean a description of me as a fumble-fingered knuckle-draggin' baboon. I also drool in my sleep. I firmly believe that true happiness is a warm gun. Did I mention how much I HATE auto-correct on this blasted tablet.

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Spindrift posted this 21 February 2021

I have a few 4, 5 and 6- cavity aluminum moulds. I just fill all the cavities, starting from one end. But I alternate the direction of fill. This seems to improve the quality of the bullets, probably because it evens out the mould temperature. If you fill the cavities in the same direction consistently, the different dwell time of the hot alloy in the cavities will establish a temperature gradient throughout the mould.

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Eutectic posted this 21 February 2021

On a bottom pour pot the initial metal in the spout is cooler than the pot temperature. I have had the first cavity filled come out bad until I dumped a little alloy into the catch tray before the first fill.

Slow fill can cause rounded edges, is your fill speed constant?

I tried the ladle with multiple cavity molds and found it slow with no quality improvement.

I find some multiple cavity molds work best with individual cavity fill, some do fine with pouring a continuous sprue from one cavity to the next. This seems to be a individual mold thing.

Steve

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Glenn R. Latham posted this 21 February 2021

Thanks for all the replies! I was using 2 moulds at the time, the second was a Lee 6-cavity for a 45-190-SWC (discontinued). I filled it from front to back each time and the bullets came out great. It's an old, well seasoned mould. The idea of going the opposite direction each time makes a lot of sense.

I cast each cavity separately, shutting off the flow before moving the mould to the next cavity. I think I would make a real mess if I tried to keep it flowing!

Casting just cavities 1,3 and 5 crossed my mind, but 1 & 5 were still casting wrinkly bullets so the mould probably still needs some more break-in.

Glenn

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GBertolet posted this 21 February 2021

In gang molds, I fill starting at the near cavity, and work back. I find it is easier to pull the mold, rather than push it. Occasionally, with certain molds, I have an issue with one cavity having rounded bases, after casting awhile. If I reverse myself for a few casts, starting at the far cavity, and working forward, the problem is resolved, then I go back to starting at the near cavity. Go figure???

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mashburn posted this 02 March 2021

I have enough trouble with single and double cavity molds. I have never owned a gang mold and am perfectly happy with my single and double cavity molds. I can turn out good bullets with them and am in no hurry, I wouldn't know the least bit about filling gang molds.

Mashburn

David a. Cogburn

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dale2242 posted this 03 March 2021

I cast with a bottom pour.

I start filling from the handles back pulling the mold towards me as I fill each cavity.

I have never found the need to change to produce good bullets.

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gnoahhh posted this 03 March 2021

My only gang molds are a couple old San Diego Hensley&Gibbs, a #68 .45 SWC and a #50 .38 WC. It doesn't seem to matter what rotation of cavity fill I perform, they just chug along turning out good bullets.

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Glenn R. Latham posted this 13 March 2021

Well I cast some more bullets with this mould yesterday. It doesn't like to get hot! I'm used to casting straight WWs or a 50-50 mix of WW and pure lead, no tin added. I can usually get the mould real hot and cast nice, evenly frosted bullets that are well filled out. The moulds usually start casting partially frosted bullets not fully filled out, then as they get hotter the bullets become evenly frosted and fully filled out. This mould didn't seem to want to get to that last state. So I kept the mould temperature down by leaving it open between casts while I was moving the just dropped bullets to the back of the rag and putting the sprues back in the pot. I leave the sprue plate over the mould block so it doesn't cool down too much. Bullets came out much better this time. Photo of poor castings plus a fully frosted and fully filled out bullet from an iron CSS Hoch mould:

The poorly filled out bullets didn't do too badly from my #4 Mk1* (Savage):

That's 9 in 2-1/2", all 10 in 3-1/2" at 100 yards, 11 grains of Promo, 14 BHN and a Parker-Hale rear sight. I think this mould shows promise.

Glenn

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Larry Gibson posted this 14 March 2021

I've been casting with bottom pour pots 311/314/316-299s in 1, 2, 3, 4 and 6 cavity moulds for many years. I learned early on that with such long skinny bullets it is necessary to have a good alloy, have the alloy temp right, fill the cavities correctly and have a good casting tempo so as not to over heat the mould.

The rounded bands and inclusions in the bullets pictured illustrate the alloy is not best for that bullet. What is wanted is a good ternary alloy with 2.5 to 5.0% of both antimony and tin in it. That balances out the antimony and tim and makes an excellent alloy, especially for the bullets you are casting. WWs with lino just exacerbates the problem as the amount of antimony exceeds that of the tin and the excess antimony will not stay in solution with the lead. I suggest trying the WWs with solder and add a bit more tin for better fill out if needed.

The alloy casting temp should be 700 - 725 degrees. The alloy should be well fluxed and that heat range maintained through out casting.

When filling the cavity, regardless of order, the alloy must be into the cavity as quick as possible and should remain molten until the sprue is formed on top of the plate. The sprue plate should not be more than 1/2" below the spout. The flow should be as fast as possible w/o splattering the alloy. each cavity should be filled individually. The molten alloy should roil back up out of the hole and form a generous sprue. Do not be afraid to let it run off the plate. A large sufficient sprue is necessary so the molten alloy will properly fill out. Many do not believe how quickly the alloy cools and solidifies in the hot mould. That's what is producing the inclusions and lack of fill out along with the poor alloy.

With a proper ternary alloy, a correct alloy temp and proper casting your bullets should drop well filled out and be nice, smooth and shiny. Adjust your casting tempo so the bullets do not "frost". I fill the cavities, let the mould sit off to the side of the pot until the sprue hardens and turns mottled grey, cut the sprue off, open the sprue plate, tap the handle nut with the mallet as I open the blocks letting the bullets fall on a towel. I then close the blocks assuring proper alignment and closure, close the sprue plate, put the cut sprue into the pot (a heavy leather glove is worn in the right hand) and then repeat. Casting faster just increases the amount of rejects.

The old axiom applies when casting; "slow is smooth, smooth is fast"...... doing so I end up with a larger quantity of quality cast bullets than if I try to really "cast fast".

LMG

Concealment is not cover.........

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pat i. posted this 14 March 2021

I've used straight WWs and cast frosty bullets since I started this game for both match shooting and plinking around. Why do you think frosted bullets are bad? I've found as long as they're evenly frosted they're as good as anything else and if your mold quenching probably better.

I've been wcasting with some Lee 6 cavity molds lately and the only one giving me problems is a .32 caliber Ranchdog pistol mold. The 30 caliber rifle and 38, 44, and 45 pistol molds work fine. As for the bigger hand gun bullets I use a ladle and just run it down the mold without turning it on its side like you would a 2 cavity mold. Glenn you probably already know this but stick the front corner of the mold into the hot lead for a 30 or 40 count, wipe the lead off the surface, check to see no lead is sticking to the mold faces, and give it a try. It might help.

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Glenn R. Latham posted this 15 March 2021

Larry, your statement: "the amount of antimony exceeds that of the tin and the excess antimony will not stay in solution with the lead" is curious to me. Both linotype and magnum alloy have 3 times the amount of antimony as tin.

Glenn

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Glenn R. Latham posted this 15 March 2021

Pat,

I like to cast frosty bullets, it suits my impatient nature. The Hoch bullet shown above doesn't look very frosty but it is. It's just this particular mould doesn't seem to want to get to that "happy state." I can live with that. But when I'm quenching from the mould I like to run them very hot and touch the sprue to a wet sponge so I can cut it while the bullet is still very hot and receive a higher BHN when quenched. Plus it speeds things up. Impatience, you know....

Glenn

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John Alexander posted this 15 March 2021

One of the good things about casting bullets there are lots of "right" ways to do it. I have used several quite different approaches over the years with and without ladles and with the mold from against the bottom spout to an inch below and gotten bullets that will win matches with each technique. Lots of variables and lots of ways to skin this cat.

John

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RicinYakima posted this 15 March 2021

Casting bullets is an art, not a science.

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Larry Gibson posted this 15 March 2021

Glenn R. Latham posted this 12 hours ago

Glenn

They do indeed have much more antimony than tin. Those alloys can and do cast good bullets, didn't say they didn't. However, the problem with more antimony than tin is equal amounts of of antimony and tin up through about 5% form the submetal SbSn which stays in solution in the lead. If there is an excess of antimony it hardens within the alloy before the alloy does. That's where the graining structure and appearance come from if you've ever broken apart a linotype cast bullets. It's also why they are brittle and shatter without much malleability to them. The better alloy is one with the tin and antimony balanced, basically a 90/5/5 alloy [Lyman #2].

It is also why adding 2% tin to COWWs (97/2.5/.5) results in a much better casting alloy of 95/2.5/2.5 with the tin and antimony about equal as they then form the submetal SbSn and stay in solution in the lead. Otherwise the greater amount of antimony in plain COWWs is why they are somewhat brittle and "frost" so easily. The "frost", especially spotty frost is actually the antimony hardening seperately from the lead. It'[s also why those spots of frost many times also are shallow spots as the antimony shrinks more than lead when it solidifies. That frosting can also give "antimonal wash" in the bore which is many times confused with "leading".

For a better technical explanation, though a bit "dry", read "The metallurgy of Molten Lead Alloys" by Dennis Marshall in Lyman CBH #3 or "The Metallurgy of Cast Bullets" by Robert J. Black in Lyman CBH #4.

LMG

Concealment is not cover.........

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Glenn R. Latham posted this 17 March 2021

It had been quite a while sine I read Dennis Marshall's articles on lead alloys, so I took the time to read them again. Later in the article, after discussing SbSn, he mentions what we often hear, and that is that since tin is so expensive, only adding enough to improve castability is prudent. This fits my Scotch side....

Glenn

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RicinYakima posted this 17 March 2021

Have settled on 2 -2.5% for everything but hunting bullets (Lyman #2) and match bullets in linotype if I can get it. Dennis Marshall was a learned and wise man.

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Bud Hyett posted this 17 March 2021

The best commercial alloy I've had was 94Pb/4Sb/2Sn. The theory was enough tin to flow easily with enough antimony to harden and be heat-treatable if you desired. I shot this alloy to 1800 fps.

This was from a scrap dealer in Genoa, Illinois who is long out of business. He blended 1400 pounds at a time for several customers and I'd get five hundred pounds for myself and several others.

Farm boy from Illinois, living in the magical Pacific Northwest

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