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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
LTFB-4-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 4-die set consists of a
CORE SWAGE (CSW-1), a CORE SEAT(CS-1), a POINT FORM (PF-1) die, and a LEAD TIP
(LT-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. 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). For lead tip bullets, the core must be either very
close to the jacket mouth, or slightly longer than the jacket after seating.
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
jacket and core length combination correctly.
Page 2
Instructions for the FJFB-3-S or -M die set, Page 2
The external CS 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. An open tip is just a core seated below
the jacket mouth. You can also make an open tip hollow point by having a conical
projection on the punch that fits inside the jacket. A lead tip hollow point is made by
using a HP punch that fits the die, and a core longer than the jacket. You cannot,
however, make an open tip hollow point (contradiction in terms).
Place the clean core into the jacket, and put both into the core seating die with the
jacket mouth (open end) facing out. 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. For larger lead tip bullets, you may be able to
use the external flat base punch from the point forming die, as a core seating punch: it
should fit the core seat die closely, so that lead cores longer than the jacket would not
bleed around it.
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. 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).
Push the jacket and core into the die with the open or lead end first. The die will curve
the jacket and lead into a bullet shape. Push only far enough to make the lead extend
from the tip of the jacket, and put the ogive curve on the bullet, Do not attempt to push
lead up the ejection pin hole or close the tip to a smaller point than the diameter of the
ejection pin. For lead tip bullets you want the "stem" of lead that attaches the top to the
main core to be large enough in diameter so that the tip will not break off in handling
or feeding. Do not try to make too small a tip: this is not effective because the jacket
walls themselves, when pushed together at the tip, will cut into the "stem" diameter
holding the lead tip to the main core. You need enough extruded lead so the cavity of
the LEAD TIP die (LT-1) is filled completely.
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.
The Lead Tip die
gently reshapes
the deformed lead
which results from
ejection from the
point forming die.
The internal punch
can be changed for
different shapes in
the same diameter.
The external punch
is the same one
used in the Point
Form die (shown
here is a Hollow
Base punch).
The internal LT punch
matches the caliber
(diameter) of the die set,
and is also matched to
the ogive curve of the
point forming die.
However, you can specify
flat tip, sharp tip, or semispitzer (rounded) tip all
with the same ogive.
Use the LEAD TIP FORMER (LT-1) to gently push the lead tip to perfect shape,
shearing off any extra lead as a little ring against the jacket. The lead should be large
enough so that it can form nicely, without voids or pits. The pressure used is extremely
light: just enough to shape the blob of lead into a nice tip, no more. If you press too
hard, a ring or step will be formed in the ogive of the bullet.
Core
"stem"
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