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Corbin Handbook and Catalog No. 7 Chapter 06
.he CHAPTER 6 CORBIN HANDBOOK AND CATALOG NO. 7, PAGE #.op
SWAGING WITH THE HYDRO-PRESS SYSTEM
The manufacture of custom bullets has grown tremendously in the
past decade: people with a diverse range of jobs (and quite a few who
were between jobs), people who had successful professional careers,
have found custom bullet manufacture to be pleasant, profitable, and a
wonderful way to plan a comfortable retirement income or to build a
business at low cost that can be turned over to a son or daughter.
There is no typical custom bullet maker, as far as I can tell. I
know doctors, carpenters, locksmiths, attorneys, laborers, people who
had severe physical handicaps, people who are the picture of a robust
outdoors athlete, people with gruff personalities and a lot of
mechanical aptitude, and people who are extremely pleasant, quiet types
who have a hard time with a screwdriver. All of them seem to be doing
quite well in the custom bullet field.
Today, you can purchase a complete package, ready to start
production of bullets so advanced, and so difficult for mass
production, that none of the big names in bullet making can compete
with you. It may seem hard to believe, but none of them have machinery
capable of forming some of the extremely tough, thick jackets, in
heavier weights of large calibers, that you can easily make on a small
machine that fits in your den or garage.
The reason they don't (and can't) compete in so many areas is
their committment to volume. Their very size dictates that limited
production items are not profitable to them. The wiser executives at
these firms welcome my customers into the field: they know that the
need for quality specialty bullets can be met by custom bullet makers
and that there is no direct competition, but in fact a benefit: they
can now forget about pressure to make unprofitable (to them) small
runs, and just refer clients to you, the custom bullet maker.
Besides, the kind of equipment needed to mass produce heavy walled
jackets in larger diameters is extremely expensive. The stroke length
and tonnage of the multi-station presses for high speed production is
quite beyond anything used for ordinary target and smaller diameter
hunting bullets. It would cost a minimum of half a million dollars to
install the equipment required, and the market for specialty bullets of
this kind is far too small to be investing even that kind of money, not
to mention the promotion, inventory, and special materials required.
On the other hand, what is unprofitable to a big outfit is enough
to keep a family or two living in high style! A custom bullet
typically is sold for prices from 50 cents to over two dollars per
bullet. They are NOT price competitive with mass produced bullets, and
they don't have to be. Even at twice those prices, there are between
ten thousand and one hundred thousand (typically fifty thousand)
bullets sold in any given specialty size and caliber each year, on the
average.
Who pays that for bullets? People who own exotic calibers.
People who like to hunt big game and have experienced repeated failures
of cheaper mass produced bullets. People who want a specific weight or
style in some caliber and don't mind investing a little more than usual
to try it. People who... well, basically, people interested in
something better, different, or unavailable elsewhere at any price.
You don't sell a lot of these bullets to local plinkers, of
course. But serious competitors, people spending five thousand dollars
or more to make a trip to Africa for hunting, special police teams who
need bullets of unusual design for tactical situations, and the
everyday handloader with a spark of curiosity in his soul -- these
people are the ones who produce backlogs for my customers, often
cleaning out their entire supply at trade shows or by magazine
advertising sales.
The machine that makes it possible is the Corbin Hydro-press.
Everything about the machine is designed so that you can get into the
field at minimum cost, and grow without having to worry about
outgrowing the capacity of the equipment. It is capable of forming
solid brass bullets in one stroke, making a 10-gauge shotgun slug from
a chunk of raw lead, forming partitioned jackets in heavy tubing,
making brass, copper, or even steel jackets with thin or heavy walls,
and extruding lead wire in any diameter.
It can turn right around and reload some ammo for you, too, using
regular RCBS type dies and shell holders. When you suddenly realize
that all your reloading presses are now complex progressives or
turrets and you have lost the old rugged simplicity of a powerful
single-station machine, the Hydro-press greets you with a "can-do!" and
barely begins to unleash its tremendous power on jobs that would
shatter the fragile parts of modern reloading machines.
It's not large -- only 34 inches tall, 23 inches wide, and 15
inches deep (about like a small refrigerator). But the design is the
essence of rugged simplicity. We use a Hydro-press to cold-forge steel
parts (used in other Hydro-presses, by the way!). It can stamp, blank,
coin, trim, and punch steel, in addition to its regular duties as a
profit center for your bullet making.
The major advantage of the Hydro-press is its built-in electronic
controls and logic circuits: the "brains" of the press and the
sensitive transducers that tell it what is going on in the world.
Anyone can assemble a hydraulic cylinder to a ram, somehow adapt it to
a set of dies, and let it slam blindly back and forth. That won't make
good bullets, however. The ability to control pressure in the die,
exact position of the punches, and precise amount of time that the
pressure is being applied, is needed in order produce a consistently
good product.
The Hydro-press uses transducers that sense the position of the
ram and control its movement though logic circuits. The earlier
versions used high quality limit switches to tell top, bottom and
loading position. Current versions use electronic proximity detectors
that have no moving parts and do not contact the ram. Solid state
timing controls the application time of the pressure. Pressure
transducers control the level of pressure applied. All this is
automatic, locked away in the steel innards of the cabinet.
What you see is a colorful Lexan-laminate-on-steel top panel, with
a digital counter, adjustable inspection light, key-locked power
switch, selector switches for various modes of operation, and brightly
colored oversize push-buttons to cycle the press. At the left rear
corner of the cabinet is a massive steel press head with inch-thick
plate for a base and head, and hardened, ground tool steel ram and
guide rods running on bearings.
As powerful as it can be, the Hydro-press is also sensitive. You
can set the pressure, speed, and timing in seconds. It can reload a .25
ACP case just as easily as it cold-flows a solid hunk of copper. Blind
force cannot begin to accomplish the tasks you can handle with the
intelligent Hydro-press system. The dies and tooling for the Hydro-
press are capable of sustaining much higher pressures than smaller dies
for the reloading press or Mity Mite. They use 1.5-inch diameter
blanks, with 1-12 TPI threads. The press head accepts a floating punch
holder with 1.5-inch by 12 TPI threads, and an adapter for standard
7/8-14 TPI dies as well. The ram can be adapted to 7/8-14 TPI, or to a
conventional shell holder. Shell holders for 20 mm and for 50 Browning
Machine Gun cartridges are also available.
Fifty caliber MG dies (for reloading) are made by C-H Dies and
they fit directly into the head of the Hydro-press. I recommend them.
Corbin builds a lead wire extruder kit, jacket maker kits, and of
course the full range of bullet swaging dies for the Hydro-press.
Calibers are virtually limitless. No small arms bullet is too
large. Weights and styles are also quite open to a wide range of
designs. If you want something that cannot be made in a hand press,
this is the system that is most likely to handle it. (If the Hydro-
press won't handle it, chances are it cannot be done.)
The dies and punches are massive, far too large for use in a
reloading press or the Mity Mite. And smaller dies do not fit into
this press for good reason: it would be too easy to destroy the dies
by using pressures only a Hydro-press die of that caliber could
sustain. All of the kinds of dies previously discussed are available
in this system. They work the same way. The only difference is that
the die goes into the ram so it faces straight up, and the external
punch fits into the floating punch holder so it faces straight down.
This arrangement makes it possible for you to drop a component
into the open mouth of the die, then move your hands back to the two-
hand, safety controls to start the stroke. In the key-locked manual
start mode, it would take a contortionist to put a part of their body
in the way of the moving ram. (An automatic mode, controlled by the
key switch, is also available -- you need to know the code sequence to
start it. It is handy for sizing long runs of cartridge cases with the
ram set for a moderately slow travel).
Rather than describe all the modes and controls of the Hydro-press
here, I will refer you to the book "POWER SWAGING", which is all about
the use of power presses including the Hydro-press. Basically, the
adjustment is still done with the punch holder, just as it is in the
Mity Mite. The main difference is that you can control exactly where
the start and stop of the stroke takes place, so that the stroke length
is adjustable to precisely what you need for any job. (Up to six
inches of stroke can be used, if need be!)
The press can stop and reverse itself, after a applying pressure
for whatever time you tell it (0.1 to 10 seconds). It will continue
down, eject the bullet gently to the top of the die, and then raise
slightly to retract the internal punch so you can put another component
into the die. The point at which it reverses can be a physical
location set by the position transducer, or it can be a pressure level
achieved by the compression of the material, sensed by the pressure
transducer.
Naturally, if you set the press to stop when it reaches a certain
position, it is possible to adjust the punch holder so that the bullet
has yet to be contacted, or so that it is pushed too far for the shape
you want. I like to set the stroke length first, leaving myself enough
room to easily put components into the die but not wasting time moving
the ram any further than it needs to go. Then, after I have a pleasant
working stroke length set up, I back off the punch holder, put a
component into the die (core, jacket, whatever I might be doing at
the time), and run the press ram up to the top of its stroke.
With the position switch and pressure switch both turned off, the
ram will simply stop when it reaches this point. It is now as far up
as it will go during this particular job. Then, I screw the punch
holder down by hand, until the punch contacts the material within the
die. I back the ram down slightly (press the green "ENERGIZE" and
yellow "DOWN" buttons, then release them after the ram moves down a
bit). Then I give the punch holder another quarter to half turn
downward, just to put some compression on the component on the next up
stroke.
The ram is then moved up (press the green "ENERGIZE" and the red
"UP" buttons). Again, with pressure and position switches turned off,
the ram will do one of two things: if the component is being
compressed and is resisting with pressure equal to that of the press
(as read on the gauge), then the ram will simply stop and hold the
pressure. I can read it on the gauge, and I can hear the motor and
pump inside the cabinet as it pushes oil over the by-pass valves. Or,
if the pressure I have set is great enough to move the component into a
more compact shape, so that the position sensor is activated, then the
pressure gauge will drop to zero, the red LED light on the top position
sensor will come on, and the ram will stop. The motor and pump will
make their usual idling sound.
It's easy to tell whether or not you have formed the component to
a limit that was set by position or by resistance to the pressure. In
some jobs, you want consistent pressure. This would be true of a core
seating operation. The Hydro-press can form seated cores far more
accurately than you can do it by hand, on the larger calibers. (On
small calibers, I still think a person can do it better -- given enough
experience).
But on a core swage operation, or when making a lead bullet with a
LSWC-1-H (note that the die designations are the same as the Mity Mite,
except that the letter "H" is added to indicate the big Hydro-press
design), using constant pressure would simply move all the lead out
through the bleed holes! It would come out very consistently, under
the precise control of the pressure and logic circuits, but there would
be no indication of when to stop pressing.
In this operation, you adjust the pressure sensor to a value lower
than that listed in "POWER SWAGING" as maximum safe pressure for the
caliber of die. Then, you actually stop the ram using the position
sensor (turn on the "POSITION" switch). The location of the top
position transducer will control the length and weight of the bullet in
this case. It is extremely important to use sensitive, high-quality
transducers for this kind of work, because variation in their range of
sensing will cause variation in bullet weight. I use a highly precise
electronic proximity detector that can sense position within millionths
of an inch, far better than the human eye.
In manufacturing a bullet jacket with the Hydro-press, the same
basic steps are used as with thinner materials in the Mity Mite.
First, a piece of tubing is cut to length. The length is determined
experimentally and is different for various weights, styles of tip,
ogive radius, and kinds of bases, as well as for partitions or
conventional cup jackets. (We work this out when we build the dies --
design is a large part of the making of a tubing jacket set).
Tubing is cut to length using a turret lathe with air feed, or an
automatic screw machine. Corbin cuts tubing for customers, and
furnishes the correct temper and wall thickness, alloy and length to
make the bullet you order. Or, you can farm this out to a local job
shop, or cut the tubing yourself with a fine-tooth saw (bandsaw,
circular saw, or even a hand saw, using a V-block and a stop to get
even, square cuts).
Boxes of from 100 to 5000 pieces of tubing are normally purchased
with the dies. One end has been deburred and chamfered. The other is
left with as much of the cut-off burr as possible on it. It will form
the base, so any extra metal is welcome and causes no problem. The
piece of tubing is placed over a punch that fits precisely inside, with
a length that allows at least half the caliber length of tube to
protrude beyond the punch tip, unsupported.
The punch has a shoulder that presses on the other (chamfered) end
of the tube. One simply installs the END ROUNDING die (or, as some call
it, the JACKET MAKING die) in the press, making sure that the steel pin
that passes through the punch head is indeed installed correctly (on
top of the knock-out bar, but under the retraction spring -- pictures
in POWER SWAGING illustrate how). Thof tube to
protrude beyond the punch tip, unsupported.
The punch has a shoulder that presses on the other (chamfered) end
of the tube. One simply installs the END ROUNDING die (or, as some call
it, the JACKET MAKING die) in the press, making sure that the steel pin
that passes through the punch head is indeed installed correctly (on
top of the knock-out bar, but under the retraction spring -- pictures
in POWER SWAGING illustrate how). Th end of the tube will now be rounded like a round
nose bullet, and will have a small projection on the end. If the tube
isn't closed this far, check the position sensor and make sure that the
right pressure is being used, and the position sensor isn't coming on
before that pressure is reached. (If it is, move the floating punch
holder down a bit -- don't adjust the position sensor).
The next step is to draw that piece of rounded-end tube to a
diameter that will fit into the core seat die for your caliber. Draw
dies are part of the jacket-maker package if they are required. Again,
it is the working system you are purchasing, with all the development
and testing that went into making it work with as few steps as
possible, not a specific number of parts. We provide what it takes to
make the jacket. Sometimes it takes thousands of dollars worth of die-
maker labor to develop some little change that you might desire, but we
don't charge you for it. On the other hand, if we can come up with a
process that eliminates one or two steps by putting in all this work,
then I think you can see that it's a better deal even if you don't need
some specific die or punch that might otherwise be included.
I mention this because not every jacket design is made the same
way. Some alloys, thicknesses, calibers, or combinations of jacket
features take differnt paths during production. Because this is almost
entirely unique, one-of-a-kind development work done just for you, to
make your bullet, it is impossible to predict whether your set will
include any given number of punches, dies, or whether certain steps
will be necessary in advance. Instructions are written after the set
has been developed and tested. Generally, they all follow the process
oulined here. Sometimes there are radical exceptions.
Rather than charging you for full shop time every time something
requires a lot of working out, we just have one standard price for a
package of tools we call the "Copper Tubing Jacket Maker Set", or
"CTJM-1-H". This set is NOT a fixed physical number of parts, but
varies with whatever is needed. You are purchasing the completed
concept, the process of manufacturing something that no one else in the
world has worked out quite this way. If it takes an extra die or two,
then the extra material you got may be considered a bonus -- I would
consider it unfortunate, since it makes the bullet manufacture a little
slower. On the other hand, if we were able to eliminate everything but
one or two dies in the set, you might consider it an over-priced set if
you just looked at the parts received and not at the time that went
into developing this faster, easier method for you. I would consider
it a blessing that someone had eliminated all the extra steps in my
bullet making operation!
But, as I was saying, the next step is usually to draw down the
end-rounded tube. For this, a die is provided. The die fits into the
head of the Hydro-press, using an adapter that takes it from 7/8-14 TPI
to the 1.5-inch by 12 TPI press head. Adapters are available
separately, if you want to permanently install one on each die for
convenience, or you can use the one that comes with the press, and
simply change the dies.
A very long punch is provided, with a base that looks like a die.
It screws directly into the press ram. This drawing operation is
exactly a mirror image of the usual swaging set-up. The die and punch
positions are reversed, and of course there is no internal punch since
the draw die is an open, annular or ring die. The tubing is simply
dropped over the punch and pushed through the die, coming out the top.
After drawing, the tubing normally must be annealed to avoid
cracks in the base. We make a very nice electronically controlled
furnace for this, which can be optionally equipped with a Nitrogen
atmosphere for even greater control (no scale, no oxidation). If you
don't feel ready for the electric furnace (which is the same quality
that we use to make our dies, by the way), then a propane or gas
welding torch will do. Heat the tip red and drop the jacket in water.
The water quench is to knock off scale. It doesn't do anything for the
anneal.
Now remove the draw die and punch, replace the floating punch
holder, and install the regular core seating die from whatever swage
set you plan to use with these jackets. Some kinds of jackets,
especially partitioned ones, have a different internal punch to
install. Instructions will be included with those sets to tell you
how. Otherwise, just use the normal flat internal punch. The external
punch is a special one in all cases, however.
The external punch is made for a specific wall thickness and
length of tubing. It fits into the jacket, supporting the walls while
pressing on the open mouth. The length of this punch is a bit shorter
than the end-rounding punch, but otherwise they appear to be similar.
The END-FLATTENING punch, as it is called, fits inside the drawn jacket
snugly, but it does fit. The end-rounding punch only fits inside the
tubing, before drawing.
As with most swaging tools, sorting out the parts is just a matter
of knowning what they are supposed to accomplish, then seeing if they
fit into the parts they are supposed to fit. If they don't fit by
hand, chances are they are not the right parts. If they do, then they
probably are!
The purpose of the end-flattening punch is to flatten the rounded
end of the tube, and make a closed jacket. Application of the
recommended pressure, as given in the instructions that come with the
set, will produce a flat base. The jacket is now finished! It can be
used just like any other jacket. The operation just described can be
applied to the Mity Mite system, using the 0.030-inch wall tubing
suitable for this press. Tubing jacket manufacture is considerably
easier and faster on the Hydro-press, even with thin jackets, since the
stroke length is considerably greater and the press has full power
anywhere in the stroke.
The Mity Mite and the Hydro-press systems both use different size
dies, and do not interchange. The Hydro-press can use reloading press
swage dies, though I don't recommend the practice: it's too easy to
over-stress a swage die by applying more pressure than the recommended
limit (the charts in POWER SWAGING are for Hydro-press dies, not the
smaller diameter reloading press dies). However, the Mega Mite press
is a common ground for all Corbin dies.
