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