Part3 – Case Flaring
Ps. we will look at powder charging in a separate entry. As it is a very
important part of reloading we need to give it the attention it deserves.
Warning – this will
only apply to 9mmp loads as it is by far the most reloaded cartridge in SA.
Loads discussed are my own. Do not copy them, do a proper safe load
development.
Remember in part 1 where we sized the case, well the sizing operation
has now made the case mouth a little too small to fit a bullet.
We now need to expand/flare the case mouth to easily seat the bullet.
This operation with a Lee die setup happens with the Powder Through Die. As the
case enters the die, the expanding plug does 2 things; flares the case mouth
and activates your Powder Measure.
Why do we need to flare the case mouth?
If you do not flare the case mouth 2 things can happen; the bullet can
collapse the case in the die or the case can shave the bullet.
Now with a CMJ – complete metal jacket – bullet you do not need to flare
the case mouth as much as with a Coated Bullet. CMJ bullets, like the Frontier
Bullets we have in South Africa are sized to .355 inch. The base of the bullet
is also rounded which helps guiding the bullet in the case.

But Coated Bullets are sized to .356inch. And the base of the bullet is
not as rounded as a CMJ.
But more importantly
so that the case does not shave any coating or lead of the bullet! This is a
crucial part in loading CoatedBullets, if the coating is removed your bullet
will tumble out of the barrel and will cause leading in the barrel. Leading can
cause a build-up in the barrel and increase the pressure…things you want to
avoid!
Flare just enough to avoid the above problems. Flaring too much will
lead to poor case life. If your bullet can sit square on the case in the shell
holder and not fall over if the ram or shell plate moves it should be ok. Too
much flare can also cause problems in your Bullet Seating Die.
Now how do you adjust the flare? Again, this is the steps to take with a
Lee Pistol Powder Through Die. Other makes have different setups and even
different dies to do this.
Make sure you have the
correct shell holder installed if you are using a single stage or turret press,
same goes for a progressive press. Make sure you have the right shell plate
installed. Raise the ram/carrier to the top of the stroke. Keep pressure on the
ram/carrier.
Turn the die in until
it makes firm contact with the ram/carrier.
Drop the ram/carrier and
turn the die out 1 full turn, at this setting the Lee Pistol Powder Though die
will not add any flare.
To add flare, turn the
die back in. ¼ turn in is usually enough for a CMJ and ½ turn in si enough for
a Coated Bullet.
Note.
If you have a newer
die set you should have a stepped expander in your die, if you do you only need
1/8 turn in for a CMJ and ¼ turn in for a Coated Bullets. To check take the
expander out of the die and look for a step like below.
This die
should never touch the shell holder or shell plate!
To test the flare…
Connect your powder
measure to the die, with no powder in! You do not need to set it up exactly
now, just ensure it is fully turned into the die.
Take a sized case and
insert it. Use a sized case only – remember a fired case expanded and the case
mouth is too big.
Make sure the Powder
Measure is activated.
On the down stroke you
should feel a bump as the expander plug flares the case mouth.
Set a bullet on the
case, make sure it is square on the case and will not fall over.
If you need more
flare, turn the die in. Less flare turn the die out.
Secure you die body.
Do not flare too much! Do not let the die contact the shell holder/shell
plate. Look for shavings if you are loading Lead Cast Bullets.
Up next we look at adding a powder charge…
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