weight varience / alloy

[XWrench3]

i have a 30 caliber lee rifle mold that is supposed to cast 200 grain boolits. it casts BEAUTIFUL .310" diameter boolits, that drop out at 178 grains with an alloy of 2/3 wheel weights, 1/3 linotype. i suppose that the 200 grain advertisement is with pure lead. i checked with lee, and the boolit length, mold number, and so is the diameter. will the alloy make THAT much difference in weight?

[plainsman456]

I have noticed that with some of my molds.
You can regulate the weight by increasing the lead or reducing the linotype,how much I can't say.
That's part of the art thing with casting boolits.

[Bret4207]

i have a 30 caliber lee rifle mold that is supposed to cast 200 grain boolits. it casts BEAUTIFUL .310" diameter boolits, that drop out at 178 grains with an alloy of 2/3 wheel weights, 1/3 linotype. i suppose that the 200 grain advertisement is with pure lead. i checked with lee, and the boolit length, mold number, and so is the diameter. will the alloy make THAT much difference in weight?

Apparently it does. If it's the same length/diameter as specified then it's pretty much got to be your alloy, doesn't it?

[XWrench3]

Apparently it does. If it's the same length/diameter as specified then it's pretty much got to be your alloy, doesn't it?

well, THATS a lot of help, isn't it. did you ever think the mold may be mis manufactured, or the specs given are wrong?

[Cherokee]

I would not be concerned if the bullets are "BEAUTIFUL .310" diameter boolits" and they shoot good. 10% lighter is more than I would expect, but if it works, fine with me. You could use less linotype. I use WW+2% tin for my rifle bullets.

[runfiverun]

since each manufacturer uses a specific alloy to designate thier weights and diameters rcbs 1-10 tin alloy, magma 2/6/92, and lyman 5/5/90.
they also have tolerances they follow so you actually get a range not an exact.
your use of another alloy will have a different outcome in weight and diameter and may or may not fall in thier tolerance range.
you are using approximately a 2/6/92 alloy which would help your diameter and lower your weight if they are using ww's as thier alloy.
but it's lee who knows what they spec or use for a range or alloy??.

[Bret4207]

well, THATS a lot of help, isn't it. did you ever think the mold may be mis manufactured, or the specs given are wrong?

You said it was on pretty much on- "i checked with lee, and the boolit length, mold number, and so is the diameter." which I took to mean you checked and the length, design and diameter are as spec'd. So yeah, your alloy CAN make that much difference. If you think it's mismanufactuered then don't come down on me, talk to Lee.

[Iron Mike Golf]

but it's lee who knows what they spec or use for a range or alloy??.

The Lee mold instructions state the bullets weights are using 10:1 lead to tin alloy.

[Mavrick]

When I buy a mold, I get one in the weight-range that I want. Ie, I want something about 200gr, I cast some up then weigh them. I'm using a different alloy than they built it to. The difference isn't going to make a difference in the powder charge as I'm going to start a bit lower, anyway, then work up. With a cast rifle load I PROLLY won't be going over, or near max.
The next time I cast that alloy in that mold, I'll compare (in my note book) the weight of a handful of the new boolits to see if my alloy has changed from the previous cast. I MAY need to make small alloy changes, from time to time.
I use WWs as my basic start point, then add componants in chemical form, ie, bar tin, or pulverized antimony. The smelted WWs are where the variation is introduced. If it's important, I'll weigh the boolits early in the cast, like as soon as I can pick them up. The size may change during the cooling, but the weight won't.
Have fun,
Gene

[williamwaco]

Most bullet molds weights are specified with Lyman No 2 alloy.

Linotype is SIGNIFICANTLY lighter than that alloy.

I have one very popular .357 mold for a 158 gr SWC. Cast from wheel weights it casts exactly 158 grains. Using linotype it is only 150. That is a smaller variance ( percentage wise ) than you report but your alloy should cast a bullet lighter than the mold is rated for.

If they shoot good - Rejoice.

[243winxb]

Never had a bullet lighter then listed, using Lyman, RCBS, Saeco, T/C moulds.
Bullet Sizes & Weights – How to Vary Them




The bullet diameters and weights presented in this list
are based on the use of Taracorp’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 lead casting alloy used. This variation
can be as much as 1/2% on the diameter, and 8% on
the weight among the most commonly used casting
alloys. For example, a .358-158 grain 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 and heaviest weight, with
such bullets running approximately .3% smaller in
diameter and 3% heavier than bullets cast with
Taracorp's metal. Linotype will produce bullets with the
largest diameter and lightest weights. 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
alloy’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 Cast Bullets

Info from the Redding Website.

[Ben]

Lee uses 10-1 Lead Tin


Ummmmmm , that is a pretty " pricey " alloy considering today's Tin prices ! !