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.
Part3 – Case Flaring
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 Lead Cast 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 a Coated
Bullet, like the Bullet Corp/Silver Rapids/Zero Mike etc bullets are sized to
.356inch. And the base of the bullet is not as rounded as a CMJ. For these
bullets you need to flare the case more.
But more
importantly so that the case does not shave any coating of the bullet! This is
a crucial part in loading Coated Bullets, if the coating is removed your bullet
will act like a normal lead cast bullet and can cause leading and even tumbling.
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 just in the case in the shell holder and
not fall over if the ram or shell plate moves it should be ok.
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.
·
Set the lock ring as far up on the die as it
will go.
·
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. 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.
·
To add flare, turn the die back in. I have found
that a ¼ turn in is enough flare for a CMJ and ½ turn back in is enough for
Coated Bullets. Very important 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.
·
Finger tighten the lock ring.
Do not flare
too much! Do not let the die contact the shell holder/shell plate. Look for
shavings if you are loading Coated Bullets.
We will test
this further when we seat our bullets.
Up next we
look at adding a powder charge…
