The CORE
SWAGE
(CSW-1)
screws directly
into the press
ram, and
adjusts the
lead core
weight.
Internal punch
External punch
fits into the
FLOATING
PUNCH HOLDER
in the press
head.
How to Swage Bullets Using The
FJFB-3-S or -M Die Set
Type -S dies are 1-inch in diameter, with a 5/8-24 shank, and fit into the ram of the Corbin
CSP-1 All-Steel press. The type -M dies are 3/4-inch in diameter, with a 5/8-24 shank, and fit
into the ram of the CSP-1 or the CSP-3 Silver Press (horizontal). The 3-die set consists of a
CORE SWAGE (CSW-1), a CORE SEAT(CS-1), and a POINT FORM (PF-1) die, each with one
internal and one external punch.
The external punch is held in the floating punch holder, a long, black, 7/8-14 threaded cylinder, which comes with the press. A threaded bushing is removed from the bottom of the punch
holder, and a round bushing inside the punch holder drops out, and is placed over the external
punch, and then screwed back into the bottom of the punch holder to secure the punch. The
punch holder screws into the press head, so the punch faces the ram. (Large diameter punches
have their own captive threaded bushing: do not remove this from the punch.)
The die screws into the press ram, with its internal punch inside the ram. A stop pin in the
front of the CSP-1 press or the top of the CSP-3 press contacts the tail of the internal punch
during the back stroke, stopping the punch movement as the die continues back, and thus
ejecting the part from the die.
Never try to swage a component that will not go into the die by hand. The swaging operation
depends on each component being slightly smaller than the die bore, and increases the bullet
diameter a little with every step. The core seating die and point forming die are matched to
each other for a given jacket and core material to within 0.0005 to .0008 inches with the core
seater being smaller. Use a small amount of CORBIN SWAGE LUBE (CSL-2) on the cores and
the jackets before each operation: moistening the fingertips with lube and handling the materials is generally sufficient.
The first die is the CORE SWAGE. It has three small bleed holes in the circumference. It is
used to adjust the lead core weight precisely, and to size the cut or cast lead cores so they fit
into the bullet jacket. The lead should fit easily by hand into the die before swaging. Adjust the
punch holder closer to the die to make the core lighter, and adjust it away from the die to
make a heavier core. Try to always swage at the very end of the stroke, so that you get
maximum leverage with minimum effort. The force required should never be so great as to
bend the punches or crack the die. Type -M dies are for use with pure soft lead only. Type -S
dies can be used with lead up to Bhn10 in hardness, not not greater. Lead resistance to flow,
and thus internal die pressure, goes up with the square of the Bhn hardness: doubling the
number from 5 to 10 makes the pressure go up four times!
Too small OK Too large
The CORE
SEATER (CS-1)
can be used with
a variety of
internal and
external punch
shapes for
various base and
nose configurations.
Cut or cast your lead cores so they are within about 5-6 grains of the desired weight, but on
the heavy side. To find out the correct weight, weight the jacket and cut lead cores to go with
it so the combination gives you your final bullet weight plus about 5-6 grains. Then swage
away the extra weight in the core swage die, for perfect cores. Clean the cores free of any lube
BEFORE putting them into the jackets (hot water and detergent in a pan will clean them:
spread them out to dry on a towel afterward).
The second die is the CORE SEATER. Seating the core means to press it into the jacket and
expand the jacket to nearly finished diameter. Jackets are undersized as produced, and depend on core seating to achieve their proper diameter. The external punch for the core seater
must fit the jacket, rather than the die, if you intend to make open tip bullets. If you intend to
make lead tip bullets, the punch may fit inside but close to the end of the jacket at the point
where the lead will be seated. Or for a large lead tip it may have to fit the die bore rather than
inside the jacket. Core seating punches are designed for a given jacket wall thickness, taper,
and length of core (weight) so you may need more than one to cover a variety of jackets and
weights or styles. If lead spurts around the punch, or if the punch digs into the jacket wall,
your bullets will probably be undersized because the pressure will not build sufficiently to
expand the jacket. The solution is to change jackets, core length, or get a punch to fit the
Instructions for the FJFB-3-S or -M die set, Page 2
The core seating die (CS-1-H) is NOT used when making rebated boattail bullets:
instead, a pair of RBT dies is used in sequence to seat the core. The external punch
can also have a projecting cone on the end to make hollow points. The internal
punch can be flat, domed or have a conical projection to form the mirror image of
that shape in the bullet base.
Place the clean core into the jacket, and put both into the core seating die with the
jacket mouth (open end) facing the die mouth. Move the ram gently forward and
align the external punch with the jacket mouth, then adjust the external punch so
that the core will just be expanded to the maximum allowed by the die as the press
reaches the end of the stroke. The force should be quite gentle, never enough to
crack the die or bend the punches. If the jacket and core stay together in the die
when the ram is moved back, rather than coming out with the external punch, it
means that they have been expanded enough to grip the die walls. If the jacket sticks
on the external punch, it may be removed by holding the pressure for a count of five
and then ejecting, or by removing the punch and tapping on the jacket mouth with a
brass hammer while rotating the punch several times (this expands the jacket and it
falls off by itself). Sticking can be caused by improper fit of punch to jacket, or not
enough lube on the punch tip.
The seated core and jacket should be just slightly under finished diameter. For
example. a .308 bullet should have a seated core and jacket of about .3078 to
.3079 inch diameter. About .0002 inches is a reasonable amount to expand in the
final point forming operation, which is next.
After seating all the cores in the jacket, remove the core seating die and punch, and
install the POINT FORMER (PF-1). This die has the ogive or nose curve shape
machined into the die cavity itself. It does not form the nose using a punch. The
internal punch is in reality only an ejection pin, and is retracted out of the die cavity
during swaging so it plays no part in the shaping of the bullet. The ejection pin has a
long head with a slot across it. The stop pin in the press frame must be removed and
then inserted into the slot, so it holds the internal punch secure to the frame. If you
fail to secure the ejection pin punch this way, it may be destroyed when you try to
eject the bullet. Push the seated core and jacket into the point forming die using an
external punch that matches the base shape. (If you change base shapes in the core
seating operation, you will need a matching external punch for the point former).
The POINT FORMER
(PF-1) uses an
internal punch
called the "ejection
pin". A slot in the
head of the ejection
pin fits the STOP
PIN on the press
frame.
During the back or
ejection stroke, the
stop pin holds the
ejection pin punch
while the ram and
die travel back
together, forcing the
bullet to be ejected
by its tip.
A point forming die is made to use a certain kind of material and lead hardness.
While it may work with other materials and hardnesses, the diameter of the resulting
bullet may change slightly. For best results, use the same jacket and lead materials
that were used to develop and adjust the dies. For instance, a die set developed for
using copper tubing jackets may work with standard commercial jackets, but the
diameter may be as much as .0005 to .001 inches different because of material
spring-back and pressure. The difference in diameter can only be determined by
testing with a given set of dies and materials.
Never attempt to push the jacket material up into the ejection pin hole. Push the
bullet only far enough so that you achieve the desired tip closure or until you reach
the diameter of the ejection pin itself, whichever comes first. Pushing material into
the ejection pin hole can break the die by concentrating tons of force in a tiny area.
If you need a smaller tip, use the LEAD TIP FORMER (LT-1) to gently push the end
of the jacket more tightly closed, or add a lead tip for a smooth supersonic outline. A
small hard lead shot dropped into the tip of the bullet before finishing the ogive can
be used to form a strong lead tip in the final operation. Lead tip bullets require a
much larger opening and a "blob" of extruded lead from the point forming stage, in
order to have material to reshape and a "stem" attaching the tip to the
A hollow point pistol bullet can be
made by using an external HP
punch in the core seater....
...followed by gently curving
the nose in the point former.
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