use a little help bullet size and weight

[DCB]

My mix is for a linotype 5# batch. 86% lead 3% 50/50 and 11% antimony.
BNH is 23. using a lee hardness tester.
the mold is a Lee 2 cav. 240gr .430.
cast bullet chart from Lyman Handbook.
weight should be 238grs im getting 237gr im ok with that.
Size from a .430 mold should be .4314, Im getting .427 and smaller?
I have not shot any of these the throat in my Ruger SRH measures .430-431
Im probably over thinking this BUT, I think i should be closer on the diameter.
i am casting at 850* nice looking bullets.
I tried cooler and got some voids.
What can I try to get the diameter I need. I tried quenching in water.
Thanks Dave

[Springfield]

Do you get the smaller diameters bullets using other alloys also? How do you know the mould throws .4314? What are you using that measures to 10/1000ths?

[Dieselhorses]

First of all 23 BHN is really kind of hard. Sounds like you need some more tin in there somewhere to make mold fill out better, of course a pic of your cast bullets would be helpful.

[DougGuy]

I think you are going overly hard with the alloy. One of the all around best alloys you could use for a Ruger is 50/50+2% for bhn 12-14 or thereabouts. This is a great hunting alloy, and very hard to beat in any Ruger revolver. Soft lube as well helps a lot.

You would likely see more the size you want out of the mold with 50/50+2%

[DCB]

I do have a mix that is 14bhn it was about the same but just a little bigger on the diameter they were .428- 4285. 1" micrometer used them all my life.
the .4314 number came from a chart that this mix should produce,
I thought that Harder would result in a larger Diameter and less leading.???
thanks Dave
Cant get the picture link to work

[Dusty Bannister]

Any particular reason you are casting at 850 degrees? Explain what you mean by "voids" because you might be dealing with a small sprue puddle and a bottom pour pot which will not allow the puddle to feed the cavity as the melt cools. What diameter do you get with the temp at about 725 after you pressure feed the cavity several cycles. Are you getting actual voids or just incomplete fill?

More information might help get things sorted out instead of so many guessing what you are doing. Lee molds like to be filled hot and fast and sometimes are a bit undersized from the maker. If you are using a high antimony content and 825 degrees that bullet should look "galvanized" so I suspect you are just dribbling the alloy into the mold and not allowing a vigorous flow to fill rapidly. Maybe opening up the flow and backing off the temp will get a nice slightly frosted but well filled out casting. Dusty

[Outpost75]

My experience has been that in revolvers leading is caused more often by bullets which are too hard, rather than too soft. When bullets exceed cylinder throat diameter, you are using the cylinder as a sizing die every time you pull the trigger. Not the most efficient way of doing it...

With ternary Pb-Sb-Sn alloys the bullets will grow slightly with aging by a few ten thousandths, so that they will no longer "fit" correctly.

Much better to use a softer alloy, 10-12 BHN is plenty hard enough for full charges in .44 Magnum when bullets "fit" and are properly lubricated. I size bullets to about 0.001" less than the cylinder throat size. The bullets will then slug-up to fit upon firing (which does NOT happen with a hard, quenched bullet!) but also they will still "fit" when you get around to shooting your stashed reloads you forgot about ten years from now.

Keith did nearly all of his development and testing in the .44 Special and .44 Magnum, as well as the .357 with 1:16 tin-lead, which he considered his "hard" alloy because at 11 BHN it is not scratched by a thumbnail test.

[DCB]

Ill give your Idea try.
The pot I have is a 10# lee 500W. bottom spout.
I am getting quicker at filling the cavities. I do have a good flow I think. I keep the mold on a hot plate and what see as void is where the bullet did not fill out completely, not perfect though.
They are shinny to a dull frost on the bands.
I am cooling the pot down now.
Do you put the sprue hole up against the spout ? To pressure the fill?
243336
243337

[DCB]

I have a 550* Gauge To compare to my digital.
I want to see how close the temp. is to the setting.
What do you see??
243339
243340

[Springfield]

What kind of chart can predict what size bullet a mould will produce? If a soft alloy measures .4285 I just don't see any way making the alloy harder will give you 2 thou more. The mould is just too small, IMO. And my father was a machinist, and taught me how to read a mike also. That doesn't make me an expert, but in my experience lead is too soft to get consistent reading in the 10 thousandths. And it isn't necessary anyway.

[GregLaROCHE]

Sounds like adding more tin and lowering he pot temperature would be the first thing to try. Lee’s moulds aren’t always perfect. You can always try sending it back or hone it a little bit with a split dowel and fine sandpaper.

[DCB]

Springfield, it just a reference from Lymans cast bullet handbook page 58 it states predicted characteristic of bullets cast in various alloys. this mix of linotype should produce a bullet "429421" @.4314"
And it does not with the lee mold. all I have for an instructor are the books
Now I an willing to try anything with in reason.
I will mix up a softer batch tomorrow.
94% lead 6% tin.. should give a 1?bhn 16:1 alloy.
so if my math is right 89% lead and 50/50 solder should be about right. or did I miss something.

[reddog81]

Powder coat and add some thickness or try a mold that is not of the Lee Tumble Lube variety.

[mdi]

Just wondering why you chose such a hard alloy? Water dropped linotype? Anyway, bullet mold designers determine mold dimensions for using a specific alloy to drop a certain size/weight bullet. Lyman often lists their mold specs with Lyman #2 and Linotype. I find the info in the Lyman manuals under a specific bullet in the data section. Any softer or harder alloy than that stated will produce a different size/weight. In my Lyman #3 there is a chart showing the differences in size/weight for a few different alloys...

Also casting methods (mold temp., alloy temp. pour method, etc) can vary the finished bullet size. Your .428" overly hard bullets shot in a revolver with .431" throats and prolly .429" groove diameter is guaranteed to lead the barrel and not be accurate....

[ShooterAZ]

Casting really hot @850* will result in smaller diameter boolits due to more shrinking. I'd say you need to get the alloy BHN down to 15 or even 10-12, and cast at around 725-750*. That's my suggestion. Sooner or later you'll find the "sweet spot" with temp and alloy composition.

[243winxb]

Buy some Rotometals, then you will have " real linotype" Lee molds are regulated with 10 lead- 1 Tin.

You alloy is not what you think it is OR Lee made a bad mould.

[Walks]

If it's a new Lee mold and you still have the receipt, you can send the mold back to Lee. Tell them It's dropping undersized bullets.
If It's used, well you know why it was sold. Their Warranty is only good for 2yrs and you gotta have the receipt.

My 30yr+ old Lee 44-240-2R drops .431 when cast with 16/1, .432 when cast of pure Lino.

[RED BEAR]

23 bnh is pretty hard i use 12 to 14 bnh in my BH and have never had a problem. As as sated 850 is on the hot side . You can also try a strip of heat tape from amazon very cheap. I would try softer and cooler first. But as a last resort you can lap the mold aluminum isn't all that hard to lap but if you want a .004 increase be ready for some work.

[DCB]

I am on a big learning curve. I need all the help I can get.
I will drop the temp and I have lead that is so soft its hard to get a good hardness on it.
I f I use 88% lead and 12% 50/50 what BHN should I get?
Thanks

[country gent]

I would recommend 1) getting the lead into the mould as fast as possible and pour as big a sprue as possible, maybe even a little spilling over the side. 2) drop the temp down to 700-725*. 3) maybe try a ladle to pour with this will increase flow into mould and help get the metal in place faster while its all still molten.

A little more tin may help with fill out, on the tumble lube bullets the small grooves may not fill completely but look good

[waksupi]

23 Bn hardness is more suited to loads in the 2500 fps range.

[RED BEAR]

I actually use plain soft lead for most things under 1000 fps. Feel free to ask anything your not sure about the only dumb question is the one not asked.

[Petander]

Considering your hi antimony alloy,it's the mold that is undersize,unfortunately.

Softer alloys will drop even smaller dia bullets.

[mdi]

I will drop the temp and I have lead that is so soft its hard to get a good hardness on it.
Not sure I understand this. A "good hardness" is 99% of the time between 10 and 15 BHN. I cast at between 675 and 750 degrees, depending on the alloy and mold I'm using (hint; keep a record/log just like you do for your reloads). For the first 15 or so years I cast boolits I used wheel weight alloy and concentrated on other aspects of casting; melt temp, mold temp, pour method and cadence. Once I got 98% keepers and leading free shooting I started playing with alloying...

FWIW; With a little thought and practice I got 80% keepers with casting using my Coleman stove, a 2 qt. stainless steel pot, a Lee 44 cal mold, a Lee dipper and wheel weights (I had access to many, many WWs). I fluxed with candle wax, stirred with a slotted spoon I stole from Ma's kitchen. This set up kept my 629 fed for about a year before I got more "sophisticated" and got a bottom pour pot. Years ago I read somewhere; "The only way to learn to cast bullets is to cast bullets...".

Keep tryin'!

[JonB_in_Glencoe]

The TL430-240 SWC Lee mold should drop a boolit measuring .430
https://leeprecision.com/6-cavity-tl430-240swc.html

Maybe your mold is undersized?
Lee had lots of issues with molds made before 2013.
If your mold is a newer style (post-2013), I suspect it's your technique.
It's easy to allow a Lee mold to overheat, from casting "too fast", especially with molds with large (240gr) cavities. An over heated mold will produce smaller size boolits.

[Burnt Fingers]

I am on a big learning curve. I need all the help I can get.
I will drop the temp and I have lead that is so soft its hard to get a good hardness on it.
I f I use 88% lead and 12% 50/50 what BHN should I get?
Thanks

http://www.lasc.us/Fryxell_Book_Contents.htm

Read that.

[DCB]

Thanks for the link..
I had a conversation with Pete at Lee. I am sending the mold to be inspected, along with a couple samples.
I melted some pure lead this morning and had some success on the size the temp was from 700 to 750* and points in between. Size ranged from .426 to .428.. just my confusion.
Thanks for all the help we nubies will keep you guessing " WHAT"
Ill le t you know what the results are

Dave

[Conditor22]

1500 fps is probably as fast as you'll push this in your RSBH I'd keep the BHN under 14.

http://www.lasc.us/Fryxell_Book_Chapter_3_alloySelectionMetallurgy.ht m
https://i.imgur.com/4XDVJT5.png

As others have mentioned casting hotter gives you smaller boolits (lead expands more the hotter it gets) BUT harder alloys usually drop bigger boolits.
I'm thinking the harder alloy expanded much more than a softer alloy would
I normally cast around 680-710°, if the fill isn't good I toss in a .5 oz pewter boolit or 2. only for pure lead do I get up to 750°. 850° is really hot, especially with a hard alloy.

Linotype melts at 465° so you could actually cast at 500°. I bet your alloy was like water :)

http://www.lasc.us/CastBulletNotes.htm
https://i.imgur.com/ljHSUKX.png

https://i.imgur.com/DAHZ4pk.png


------ OR, you just got a bad mold -------- :(

[RED BEAR]

If its a new mold you could send it back but considering the cost of shipping vs cost of mold it probably ain't worth it. You can inlarge your mold with a little heat tape i use the .002 thick but you can get different thickness. I worried at first because when sized they looked like they might be a little out of round but shoot great. A lot better than they did undersize. I am in love with 32's unfortunately i have found that the bores on them run from .308 to .314 at least on the ones i have and it doesn't make sense to buy a different mold for each one so a little tape works wonders.

[mdi]

I'm far from a "Casting Expert", but lead melts at about 620 degrees. The only reason to melt lead is to pour it in a mold so I started by getting my lead approx 650 degrees and watched for wrinkles and fill out. More often than not good wrinkle free bullets started around 675 degrees with a good mold temp...

I found it is necessary to "balance" mold temp and melt temp.

[RED BEAR]

I have to agree with above i usually cast as low as i can.

[Tenbender]

The powder coat is what I do. I have a 358 mold that throws 357. I powder coat and run them through a 358 sizer. Bingo ??

[greenjoytj]

Don't try to pressure cast by holding the mold against the valve outlet, you will get light off weigh bullets because there will be a void inside. You must make a sprue a puddle of liquid alloy because some of the liquid in the sprue neck gets drawn down into the mold as the hot lead cools and shrinks. The shrinking lead sucks in a little lead from the liquid in the sprue neck.

A formula from the Rotometals site:
Basic Rules for Hardening Lead-

For every 1% additional tin, Brinell hardness increases 0.3.
For every 1% additional antimony, Brinell hardness increases 0.9.
For a simple equation,
Brinell = 8.60 (Antimonial Lead) + ( 0.29 * Tin ) + ( 0.92 * Antimony )

From the Redding - SAECO catalog: Bullet Sizes & Weights – How to Vary Them

The bullet diameters and weights presented in this SAECO catalog are based on the use of TaracorpÂ’s Lawrence Magnum bullet alloy ( 2% tin, 6% antimony, 1/4% arsenic, 91.75% lead ).

Bullet diameters and weights will vary considerably depending on the casting alloy used.
This variation can be as much as ½ % on the diameter, and 8% on the weight among the most commonly used casting alloys.
For example, a .358” - 158 gr. bullet might show a diameter variation of .002", and a 13 grain difference in weight.

Of the most commonly used alloys, wheel weights ( .5% tin, 4% antimony, 95% lead ) will produce bullets having the smallest diameter ( Low tin content cause poor mold fill out ) and heaviest weight, ( Do to the high lead content ) with such bullets running approximately ⅓ % smaller in diameter and 3% heavier than bullets cast with Taracorp's alloy.

Linotype Alloy Alloy ( 4%-tin, 12%-antimony, and 84%-lead ) will produce bullets with the largest diameter ( high tin content causes better mold fill out ) and lightest weights ( Due to the low lead content ).
This alloy will produce bullets approximately 1/10 % larger and 3% lighter than Taracorp.
Other alloys of tin and antimony, with antimony content above 5%, will produce bullets with diameters and weights falling between those cast from wheel weights and Linotype.

Alloys containing little or no antimony will cast considerably smaller than wheel weights and in some cases will produce bullets too small for adequate sizing.

Within the limitations given above, the weight and diameter of a cast bullet can be adjusted by varying the alloyÂ’s antimony content.

The size and weight of bullets of a given alloy will also vary according to casting temperature.

Higher temperatures will result in greater shrinkage as the bullet cools, thereby producing a slightly smaller and lighter bullet than one cast of the same alloy at a lower temperature

[Daver7]

IF this is a case of the mold being under size could the mold be lapped out?
I'm not an expert and not saying this is a good idea, just wondering if it could be done.