cast bullet questions

[odette]

I am casting a 405gn .458 bullet from a single cavity steel RCBS mould. The bullets are dropping at 419 to 420gn and are around an 11 BHN. I am using 9 lbs wheel weights and 1 lb linotype for a mix. The bullets come out of the mould with a little frost on some, any that gas checks fit loose are discarded. I will powder coat once the gas checks and sizing is done. I am using a .459 NOE sizing die.
My questions are, will the frosting affect the ballistics. Should I use the loading data for a 405gn or the data for the 420gn lead bullets listed in the Lyman or the Lee manuals. Will adding 2 lbs more of linotype bring the bullet weight down. I am planning on loading a mild load to use in Sharps, Remington Creedmore and TC Contender, so hardness is not that important with the PCing and gas checks.
I have read some about frosting not being a big deal, but one person that has done extensive casting and competition shooting told me to remelt any that are frosted. Thank you for any answers.

[Lakehouse2012]

I am casting a 405gn .458 bullet from a single cavity steel RCBS mould. The bullets are dropping at 419 to 420gn and are around an 11 BHN. I am using 9 lbs wheel weights and 1 lb linotype for a mix. The bullets come out of the mould with a little frost on some, any that gas checks fit loose are discarded. I will powder coat once the gas checks and sizing is done. I am using a .459 NOE sizing die.
My questions are, will the frosting affect the ballistics. Should I use the loading data for a 405gn or the data for the 420gn lead bullets listed in the Lyman or the Lee manuals. Will adding 2 lbs more of linotype bring the bullet weight down. I am planning on loading a mild load to use in Sharps, Remington Creedmore and TC Contender, so hardness is not that important with the PCing and gas checks.
I have read some about frosting not being a big deal, but one person that has done extensive casting and competition shooting told me to remelt any that are frosted. Thank you for any answers.Frosting isnt a show stopper. If using coating like hitek, can actually help bonding. Try air cooling empty mold for some time longer between casts, you maybe just over the sweetspot. Try slowing in 5 second increments and see if results improve. Other item could be pot is too hot.

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[gwpercle]

I get my best fill out and most perfect boolits when casting just at the light frosty temperature.
Frosty boolits are not deal breakers.
Imperfect bases and incomplete fill out are my reasons to go back into the pot.
Gary

[Winger Ed.]

That's the .45-70 mold I use.
For mine to fill out just right, and my casting rate, using wheel weights and a handful of shot gun shot,
I always seem to end up with a tiny bit of frosting too. I haven't found it to be an issue.

[Conditor22]

Frosting is OK, just make sure to slug the barrels and get the right diameter.
you'll need to size the boolits again after you PC (unless you calculate the added diameter of PC before you size the first time.

I've helped several people with 45/70 accuracy issues because their boolits were too small.

[woody1]

I get my best fill out and most perfect boolits when casting just at the light frosty temperature.
Frosty boolits are not deal breakers.
Imperfect bases and incomplete fill out are my reasons to go back into the pot.
Gary

Me too, pretty much. I like 'em a little on the frosty side.

[Mica_Hiebert]

Nothing wrong with frosty bullets and once you powder coat youll never even know.

If for some reason you need to cast Instagram picture worthy silver bullets you can try dialing back your alloy temperature

[williamhemmings]

I have been casting for about 10 yrs. I shoot BPCR ,csharps 535 gr bullet @ 20 to 1 mix. At 500 yds+ wheel weight just consistent enough for that type of work.

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[odette]

I just did another small batch of the RCBS .458 bullet. I changed the mix, adding 1 more lb of linotype and trying to keep the pot at 650 degree. I did as LakeHouse suggested, dropped the bullet and held mould open for the count of 3 then cast another, etc.... they appear to have less frost and more shine, nice bases and crisp edges on the grooves. I will weigh them and see if changing the mix dropped the weight.
I will load them with 25.3 gn AA5744 using a Lee Disk Powder Measure with 2 disks stacked. I tried loading a few rds and they were 25.3 to 25.5, close to the starting load in the Lee manual. All the other manuals I have don't list AA powders. All are from late 70's early 80's. Hoping to find online loading data before I go any farther. My Sharps and Marlins love the Speer 400gn JFP, so I hope this lead bullet comes close to the Speer. Seems like companies like Speer and Winchester discontinue the stuff my guns like the most.

[Tom_in_AZ]

Frosting isnt a show stopper. If using coating like hitek, can actually help bonding. Try air cooling empty mold for some time longer between casts, you maybe just over the sweetspot. Try slowing in 5 second increments and see if results improve. Other item could be pot is too hot.

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[Mica_Hiebert]

Your speer bullet is back in production and available on their website.

[waksupi]

I personally cast to get frosted bullets. Fewer inclusions that way. I think you are wasting your lino, wheel weights do fine.

[odette]

Thank you Mica for the info about Speer's 400gn .458 bullets, my 45-70's will be happy. Now if only Winchester would bring back 785 powder so I can feed my .270 what it likes

[454PB]

Frosting is caused by high mould temperature. Naturally, high alloy temperature causes this, but it is easily controlled by cooling the mould. I keep a cake pan with 1/2" of water nearby, and when the frosting becomes too heavy or the sprue is taking too long to set, I touch the filled mould to a cloth or sponge placed in the cake pan.

Any time you're casting big boolits in a single cavity mould, it's going to overheat if the alloy temperature is high enough for a good casting. It's much easier to control mould temperature than melt temperature.

[odette]

I kept the pot at 650, cast same as usual but once the mould was casting nice bullets, I would leave the blocks open and count to 3. Then I closed the blocks and cast another, no frost spots. I have a Saeco .458 semi spire mould and will cast some for my Sharps and Creedmore, I will repeat this method, but will try straight wheelweight. Never cast without linotype before, I hope the bullets are full and no rounded corners.

[williamhemmings]

I kept the pot at 650, cast same as usual but once the mould was casting nice bullets, I would leave the blocks open and count to 3. Then I closed the blocks and cast another, no frost spots. I have a Saeco .458 semi spire mould and will cast some for my Sharps and Creedmore, I will repeat this method, but will try straight wheelweight. Never cast without linotype before, I hope the bullets are full and no rounded corners.
Frosting is caused by high mould temperature. Naturally, high alloy temperature causes this, but it is easily controlled by cooling the mould. I keep a cake pan with 1/2" of water nearby, and when the frosting becomes too heavy or the sprue is taking too long to set, I touch the filled mould to a cloth or sponge placed in the cake pan.

Any time you're casting big boolits in a single cavity mould, it's going to overheat if the alloy temperature is high enough for a good casting. It's much easier to control mould temperature than melt temperature.Don't know how far you expect to shoot out to but at the ram line (550 yds) wheel weights just we're not consistent enough. I know lots of shooters use them but when you consider the time and effort that goes into trying knock that ram down I don't want to do any shortcuts or cost savings.

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[JonB_in_Glencoe]

Frosting is caused by high mould temperature. Naturally, high alloy temperature causes this, but it is easily controlled by cooling the mould. I keep a cake pan with 1/2" of water nearby, and when the frosting becomes too heavy or the sprue is taking too long to set, I touch the filled mould to a cloth or sponge placed in the cake pan.

Any time you're casting big boolits in a single cavity mould, it's going to overheat if the alloy temperature is high enough for a good casting. It's much easier to control mould temperature than melt temperature.

This is a very good explanation. but instead of a wet sponge or pan of water, I use a small fan to help regulate the mold temperature with molds that tend to get overheated due to having a large cavity/cavities.

I will add, uniformity is what you want for best accuracy. But using the term "frosty" doesn't tell much of a story, just like saying "hard-cast" doesn't tell us much about what an alloy actually is.

How the boolits look, can tell you how you are casting:

Shiny with wrinkles, mold too cold
Shiny with no wrinkles, mold in the lower portion of correct temperature range.
Partially shiny and partially light grey, mold nearing ideal temperature.
Uniformly light grey, Ideal temperature
somewhat frosty, mold in the higher portion of correct temperature range.
Very frosty, almost look galvanized, Mold too hot. At this point, you may experience boolits bending/breaking when dropped from mold.

Whatever mold temperature level you cast the best boolit at with a specific mold, is the mold temperature you should cast at...and for the very best accuracy, I would cull all the boolits that don't look uniform in appearance.

[popper]

Light to mild frosting is OK but the high Sb and mould too hot will leave pits in the cast. That is BAD. When the alloy cools it alternates between Sb rich and Pb rich, hot mould allows the surface to be Sb rich alloy and it cools that way. Any tin in the alloy makes it worse. Usually the middle frosts first, base last.

[odette]

I cast a new batch using straight wheel weights and what little that was in the bottom of the pot from the last time. I tried to keep temp at 650 with some success, but thermometer flops around too much to stay accurate. Back to the cast bullets, They all dropped out of the mould looking nice, no frost, shiny and good bands and grooves. I checked hardness a day later and they are 9 BHN according to my STS dial tester. I gas checked and sized them and noticed that they were under sized, .457 instead of .459. Is this normal with straight wheel weights? I have always used Lyman #2 as a starting point , but am not very experienced. This is the first time under sized bullets came out of this mould for me. I powder coated them and will size them again, hopefully they will have better contact with the .459 sizing bushing.
What causes a casting to be under sized? Is it the mix?

[454PB]

Try raising the melt temperature to 700-725. As previously stated, it's easier to control mould temperature than melt temperature. I have three Lee bottom draw pots, and all three will maintain a set temperature within 25 degrees. The adjustment knob is only a reference and doesn't correspond to an actual temperature, and also varies from pot to pot. What I've done is to write what number corresponds to 700 degrees on each pot, using my RCBS temperature gauge.

If you're using a tin poor alloy (like wheel weights), you need a little more heat to cast boolits that are filled out well and full diameter. One of the problems with that is the "frosty" appearance. The frosting doesn't bother me a bit, and can actually be buffed off after the boolit is seated in the case. Antimony does increase the as cast diameter, so it's normal for straight wheel weight alloy to cast slightly smaller than it would with a little type metal added.

My wheel weights are all fairly old, and they hardness test at 12 BHN. If yours are newer, they may have less antimony resulting in the reduced hardness.

[Dusty Bannister]

Consider following the suggestions to increase the alloy casting temperature. The less tin and antimony the higher the casting temperature needs to be to get best mold fill out (to a point) but not so hot that you cause excessive dross from the oxides of tin and antimony. Adding one percent of tin would help with the flow of the alloy into the mold and might be key in getting better mold fill out. Consider making only one correction at a time and let the temperature stabilize and then cast long enough to get the mold up to correct casting temperature. This will help you find what factor improves your product.

You are also making a mistake when you test the alloy hardness the day after casting with a low antimony alloy. It might take up to three weeks for the final hardness to stabilize. If your castings are measuring a hardness of 9 BHN after 24 hours, it will probably be more like 11 or perhaps a little more when mature. Be patient.

When you measure the diameter of your casting, are you using a micrometer or a caliper? Do you measure at the same location on each bullet or perhaps just the maximum or minimum diameter? I hope you try to use a micrometer and take the reading on the same driving band on either side of the mold parting seam and at 90 degrees from the seam. That can tell you a lot about the casting, and the mold condition.

To avoid the frosting of your cast bullets, you may have to consider the use of a lead and tin mix and avoid antimony all together. It will not be cheap to do that. Dusty

[JonB_in_Glencoe]

I cast a new batch using straight wheel weights and what little that was in the bottom of the pot from the last time. I tried to keep temp at 650 with some success, but thermometer flops around too much to stay accurate. Back to the cast bullets, They all dropped out of the mould looking nice, no frost, shiny and good bands and grooves. I checked hardness a day later and they are 9 BHN according to my STS dial tester. I gas checked and sized them and noticed that they were under sized, .457 instead of .459. Is this normal with straight wheel weights? I have always used Lyman #2 as a starting point , but am not very experienced. This is the first time under sized bullets came out of this mould for me. I powder coated them and will size them again, hopefully they will have better contact with the .459 sizing bushing.
What causes a casting to be under sized? Is it the mix?

A bit more info would help getting you some good answers.

First, it's time to get that thermometer mounted so it doesn't flop around and gives you a good temperature reading.

Are your straight wheel weights, 100% clip-on style, or a mix of clip-on and Stick-on?

you said, the bullets looked "nice, no frost, shiny and good bands and grooves" Were the edges of the bands crisp? or slightly rounded?

you said, "noticed that they were under sized, .457 instead of .459". Did you measure unsized boolits from previous batches? Did you measure any unsized boolits from this last batch? what is your measuring procedure? I assume you are using a 0-1" Micrometer with correct techniques, are you measuring the samples on each side of the parting line to see if they are out-of-round ?

[44Blam]

So, the thing I found with casting is that the bigger the boolit I am casting the slower the cadence I cast at. I've got a 90 grain 30 cal mold that you have to race to keep everything warm. Then my .40 mold is constant movement and it doesn't really get too hot. Then I've got a 44 mag mold that I have to wait between drops. Usually, those get a little frosty and I noticed that the frosty ones are a little bigger and heavier. Then I've got some 45 caliber molds that are in the 3-400 grain range. I take my time with those and make sure to have good pressure when filling the cavities. I cast until it is hot and then cast, leave open and just go slow.
EDIT:
My 45 caliber molds are Accurate and NOE molds. I size to .460 because my Marlin likes them a little bigger...

[odette]

my previous casting with this mould dropped .460 to .461 bullets measured at the 1st band from the gas check groove. I measured the band, turned the bullet 1/4 turn and remeasured. Then I measured across the length bullet from bottom band to top band and again turned and remeasured. I use a micrometer for measuring. My previous cast was last fall with this mold and I used 9 lbs wheel weights and 2 lbs linotype and got the .460 to .461 dia bullets. They were kind of hard for me to size thru my NOE size bushing on a Lee Turret Classic press, so I sprayed them lightly with a lanolin alcohol mix. I spray then down with break cleaner and wash in hot water and dishsoap to get the lube off, dry and gas check & size them. I then powder coat and size again a day or 2 later.
I did not know about the BHN changes about 3 weeks after casting. I ask for advice at the local gunshops about casting and they tell me that know one does that anymore and very few reload anymore, so I rely on grandpas notes and the nice gentlemen here

[odette]

my old Lyman Mag 20 has seen it's better days. The paint is peeled off the top and it some times doe not turn on. Does anyone use the RCBS Pro Melt 2 or the Lyman Mag 25 Digital. Are they accurate and hold the displayed temperature well.