Sizing Die Maintenance

  • Last Post 29 June 2017
Ken Campbell Iowa posted this 04 June 2017


i am forwarding an interest post from my friend john g. ... regarding something that
may occur more often than we think . his rifle is a browning miroku m85 that now has a
douglas barrel in 357 max. and a 0.2 freebore and 1.2 degree throat . we are hoping for
good accuracy .


I got some loads developed for my 1885 Win and was loading up some rounds and discovered
a problem with one of my bullets. ( a Ranch dog bullet ) . I noticed what looked like a
small piece of lead stuck in the lube just above the gas check. I figured it was just a
piece of lead that got caught on a bullet when it was molded and it just stayed stuck on
the bullet.
Then i noticed it on the next bullet i sized. I figured I had better check the mold
but then I noticed it was always showing up in the same place on the bullet when i sized
it. so i took out the sizing die and used a heat gun on it to remove lube and see what
was wrong. When i looked in the hole, i saw what appeared to be a tiny bit of flashing
from probably the lube groove ring cavity on the die.

I took a probe and removed this:

Parts from gas checks were stuck tight in the grease groove, mostly brass and few small
chunks of aluminum. With over the few thousand bullets some checks must have been
sheared off and stuck in the die.
After i removed them from the die, it works fine and the lead spot went away.

This Ranch dog bullet is the easier of several to cast (6 gang) and i tumble lube for
other 38 calibers but for my custom 357 max chamber and throat i must size to .358 to
fit in the chamber.

This small flat base 9mm bullet i have chosen for a light load, Lyman 356402, shoots
very well under 50 yds and is one of the few flat base bullets i can shoot 1300fps with
out leading and with good accuracy. Weighs in at 118 gns, really should not shoot well
in this and other guns i have used it in ... but it does. It will do under an inch at
50 yds using 5.0 gr. of Tite Group.

Only problem is, 118gr shoots around 3.5 inches higher at 50 yds when rifle is sighted
in for the Ranch dog load. 20.0 gns of 4227 seem to work well for me, even with 4 other
cast bullets from 175 to 200 gr. in weight.

Was almost dark before i got to shoot again today, was windy most of the day till dark.
(I have such a time to get the wife to hold the flashlight on the target for me some


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JSH posted this 05 June 2017

Was this a RCBS/Lyman type die or another kind?

Now I am going to check my lube dies. I know a lot of junk will build in a seating die and cause a lot of grief for a pretty simple problem. I clean my seater dies on a pretty regular basis anymore.

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Ken Campbell Iowa posted this 05 June 2017

he thinks the sizer die was rcbs ... however he bot it ""as new "" at a gun show ...and it doesn't  have the size stamped on the top ... so there is some mystery  .  might be worth doing a slow-motion study to see how this stripping might occur .

thanks for asking, ken

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BigMan54 posted this 29 June 2017

Just discovered this same problem with one of my sizing dies. I set up my LYMAN 450 with  RCBS  .452 dia die to size some 45-201-KT.  1st bullet showed a big V shaped piece of lead stuck in the lube in the bullets groove.  I knew I had  problem. So I pulled the die out, removed the rubber O-ring  & put the die in a glass dish of acetone. After 24+ hours I pushed the "I" post out of the die and scrubbed the heck out of the inside with the small end of a G.I. toothbrush.  I didn't find any thing inside the die, so I guess whatever caused the "scraping" of lead into the lube groove of the bullet was lost in the cleaning.  It may have been caused by sizing .456 dia bullets down too far few weeks earlier. There is a groove inside the die that mates up with the holes that transfers lube from the reservoir thru into the inside & onto/into the bullets lube groove  I think that is where the crap is left behind in the die.  Then I remembered this post. Too late. But now I'm going to clean every size die I have.   I've never taken apart a "H&I" size die before. I wonder if the LYMAN dies are the same on the inside.

Long time Caster/Reloader, Getting back into it after almost 10yrs. Life Member NRA 40+yrs, Life S.A.S.S. #375. Does this mean a description of me as a fumble-fingered knuckle-draggin' baboon. I also drool in my sleep. I firmly believe that true happiness is a warm gun. Did I mention how much I HATE auto-correct on this blasted tablet.

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