hi, i am new to reloading and casting bullets , i have cast some bullets with a lee mold #tl358-swc 158 gr. but the weight of the cast are from 159 gr to 161 gr is that to much and how do i fix it ,thanks

Molds can be slightly inconsistent. You could try adding a little tin or antimony to the lead. Tin and antimony are lighter than lead and will give you a lighter bullet. The drawback is that tin and antimony will soften the lead and that can lead to excessive barrel leading so you will need to check the hardness of the cast bullet.

My advice would be to find the correct mix for hardness and let the mold drop what it will, within reason that is. A one or three grain difference is not going to cause a problem in my opinion.

Quite the contrary! Both Tin and Antimony are used to harden the alloy. You can't get any softer than pure Lead which has a Brinnell hardness of ca. 5. By adding appropriate percentages of Tin and Antimony the hardness can be increased to as mck as 22 Brinnell. The only part you got right is that these will both result in a lighter bullet.

Unfortunately, bullet hardness has little to do with reducing leading. Alloy that is too hard can result in an increase in leading. The factors that have the greatest effect in reducing leading are bullet fit and a proper lubricant.

Now, for ellisV6's original question.

ellis,

You don't say what alloy you are using, but straight wheel weight metal is really a poor choice by itself if that is what you have. Adding 2-3% Tin will improve castibility by improving metal flow characteristics.

A variation of 2-3 grains from nominal bullet weight is not only acceptable, but is actually better correspondence than is usually seen. Mould cavity tolerances in both diameter and depth can, and usually do, cause this much and even more. If you are asking about variance within bullets cast during a session, then the same answer applies. +/- 1% in weight of cast, or any bullets for that matter, is acceptable and normal. for a 158 gr. bullet 3 gr. is slightly less than this amount of variation.

Almost any change, in alloy, casting temperature, casting speed and tempo, will result in variations. Temperature being the one which will cause most variation. How, and how often you flux to clean the metal will cause changes, often by having Lead oxide inclusions in the cast.

Everything that can be done to improve consistency, a thermostatically controlled pot, as well as the largest one you can afford, will be a big help. Keep the metal level in the pot consistent, mostly to keep temperature changes when metal is added to a minimum. A spouted dipper, instead of Lee's little open ladel if that is what you are using helps as it will allow a head of metal to put pressure on the bullet as cast. Counter-intuitively, a bottom pour pot does not generally give as good consistencency as good technique with a ladle.

Here is a good article that should help you: HINTS FOR CASTING GOOD BULLETS

But I have only been casting since 1958, what do I know!!

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Gunsmithing since 1961

Good info from Alk8944.

I cast that same bullet with straight WW alloy and get bullets that weigh around 162 gr. on average. They drop oversize- around .360". I shoot them as cast in 357 Mag and 38 Special using a tumble lube made by combining Johnson's Paste Wax and Lee's Liquid Alox. I found the recipe for this "JPW" lube and lot's more good info at this forum: Cast Boolits - Dedicated To The World Of Cast Bullets!

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Andy

thanks for the help

FYI

Common Bullet Alloy Hardness

Alloy BHN
Lead 5
WW (stick on) 6
Tin 7
1 to 40 tin lead 8
1 to 30 tin lead 9
1 to 20 tin lead 10
1 to 10 tin lead 11
WW (clip on) 12
Lead Shot* 13
Lyman # 2 15
Water quenched WW 18
Linotype 18 - 19
Monotype 25 - 27
Oven heat treated WW 30 - 32
Antimony 50

Cast bullet reference on lead alloy's, min / max pressure, lube, shrinkage,

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Semper FI