Monday, March 21, 2016

Bullet Mold Galling Failing

This is a condition which occurs on bullet molds is called galling. First let us define the terms in relation to bullet molds.
 1) A sprew plate or sprews cutter is the top plate that cuts off the excess lead when you cast a bullet.
 2) A sprue is the glob of lead the speew cutter cuts off.
 3) Locking lugs are the dimples sticking out of one half of the bullet mold that aligns with a coinciding hole or grove in the other half of the bullet mold which keeps the two halves in alignment.
4) Failing bullet molds have several reasons which I will list below.
A) Galling is when the sprew cuter  rubs against the bullet mold and one or both deteriorate.
B) Ladle pour burn – This is typically found when people use pouring ladles to cast bullets. As the mold and ladle are turned the hot lead hits one side of the mold first and the steal begins to deteriorate eventually leading to an out of shaped bullet making the mold unusable.
 Bullet mold failure has several reasons depending on the mold in question. Aluminum molds are inexpensive and less durable than steal molds and so one cannot expect them to give as long a life as steal molds. The trade off is the savings in price. A galling mold has the sprew cutter chewing up the metal beneath it. This can occur on steal or aluminum molds.
Galling aluminum mold- Aluminum molds have the sprew plate fairly snug from the factory and this should be left that way. I have found that a little lubricant at the corner will help. Graphite is problematic as it will not last long and every few minutes you will need to reapply it. Bees wax should never be used in any condition on any bullet mold as it travels.
Lubricating aluminum molds. Wax, oil, grease, lard, etc has no business in a bullet cavity it will cause the bullet to wrinkle and drive you crazy.  However there is a solution for aluminum bullet molds and is best when the mold is new. First clean the mold by slushing it around in lacquer thinner. With the mold clean and dry start to cast until the mold is up to temperature. Now cast and leave the bullets in the bullet mold and move the sprew cutter aside. Using a lit candle and the end of a toothpick get the smallest amount of wax possible on the end of the toothpick, almost nothing!  Touch it by the sprew plate where the mold pivots. On one side and then do it again on the other with another toothpick. Close and reopen the mold. Look to make sure that the wax is not traveling toward a bullet cavity. Wipe away if the wax moves at all toward the cavity. Open and close the hot mold a number of times to make sure the wax is staying in place. Now begin to cast this should last for over 100 lb of bullet casting before it needs to be reapplied.
Lubricating steel molds- Steel molds should have the sprew plate adjusted so it is fairly louse so it closes just by a jerk of the wrist.  No lubricant of any type should be used on a steal mold. And the steel mold should have the factory lubricant removed with lacquer thinner before use and it should be re-lubricated for storage when you are finishes with a lite oil.
Galling steal mold – This is a hopeful post and non-definitive as I do not have any other test subjects. I have had galling steal molds before and I think it is from carbon deposit concentrations in the steal. When a steal mold starts to gall there is no stopping it. Usually the manufacture will replace it for free as long as it does not show abuse. Having a galling mold I thought I would cast until the gall worked its way into the bullet cavity. While casting I remembered that some old bullet molds were made of brass and stopped casting and let the galling mold cool. Taking the sprew plate off I took an old shell casing and gave the top of the mold a real workout by hand until it was covered with embedded brass. I have casted quit a bit with it over time and the galling has not continued.
Ladle pour burn- As mentioned this condition sometimes occurs when people use pouring ladles however this condition never occurs when using a downspout pot.  
This should give you an overview of bullet mold problems.

Richard W. Norman     Author of American Handbook on Guns Ammo and Freedom        

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