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.