Universal Case Expanding Die
Most of us tend to muddle
by, in our handloading, with the normal complement of tools to assist us: a press, die
sets, shellholders, scale and a measuring device or two. As we become more sophisticated,
we may add to this list. Lee Precision of Hartford, Wisconsin, has recently added a tool
to its impressive line that may help us fine-tune our handloading even more: the Lee
Universal Case Expanding Die.
Whats it for and
why do we need it? Its purpose is to bell the mouth of a cartridge case without expanding
the case neck. Need is perhaps too strong a word; facilitate might be a better choice.
Before we get into specific examples of how it can assist us, lets examine the tool
It looks pretty typical:
a cylindrical steel body about 3 inches long with 7/8x14 threads covering the lower 1 3/4
inches. Above the threaded area is a smooth section with LEE - EXPANDR - L2
stamped around its circumference. Above that is a knurled section followed by another
smooth section. An aluminum cap, called an adjusting screw, threads into the top of the
body. A standard Lee locknut is used to secure the body in a press. Inside, the die body
is smooth except for a threaded section at the top that accepts the adjusting screw. The
smooth interior is of two diameters. The upper section will accept expander plugs of 9/16
(.5625) inch in diameter. A lower section is slightly smaller, preventing the plugs from
sliding out of the body.
In use, one or two
expanding plugs are inserted into the body according to the case to be expanded. A small
plug has a cylindrical upper half and a tapered lower designed to accommodate cases of .22
to .32 caliber. A large plug is similar with its tapered section designed to be used with
cases of .32 to .45 caliber. It appears 8mm cases would work with either plug, depending
upon intent. The instructions are clear with diagrams and a chart that show how the plugs
are to be assembled. With cases up to 1 1/2 inches in length, both plugs are inserted into
the die body with the appropriate one taper end down. With cases from 1 1/2 to 3 inches in
length, a single plug is used.
Setup and adjustment are
simple. The expander plug, or plugs, are assembled according to the instructions and the
adjusting screw is turned into the die body until the screw threads are below the die body
surface. A case is placed in the shellholder and the press ram raised to its top position.
The die body is screwed into the press until contact is made with the case mouth. The die
body is locked in place. The press ram is lowered a bit, and the adjusting screw is turned
in about one-half turn. The press ram is raised again, belling the case mouth. Fine tuning
is done from there with the adjusting screw.
Now, back to when do we
use it? Ive encountered several situations where the new Lee tool was of use. The
first was when I opened a bag of new cases purchased in bulk. Quite a few of the cases had
mouths that were dented. Admittedly, some of the newer die sets have expander buttons with
sufficient taper to straighten out the offending cases easily, but many do not. For me, it
was easier to set up the new Lee Universal Case Expanding Die to straighten out the case
mouths without lubricating, resizing or even actually belling the mouths. I was then able
to chamfer the case mouths inside and out, as we should do, before beginning any loading
Lee literature suggests
using the die to bell case mouths prior to seating moly-coated or cast bullets. Even with
some of the new chamfering tools designed to ease bullet entry, this may be good advice
when using coated bullets with a two-die set, as is typical with bottleneck rifle
cartridges. On numerous occasions Ive seen the case mouth scrape off the moly
coating as the bullet was seated. Whether this actually constitutes a problem in need of a
solution will have to be determined by each shooter.
In the case of cast
bullets, the situation is different. With the standard three-die set used with
straight-walled handgun, and some rifle, cartridges, the use of the Lee die would be
unnecessary. That is, unless you wanted the case grip to be that imparted by a sized but
not expanded case. In that situation the Lee die could simply replace the second die,
belling the case mouths but not expanding the neck area. This scenario is more likely to
be appropriate with jacketed bullets than cast. Its been my experience in working
with a variety of expander plug diameters for a given cartridge that jacketed bullets
benefit more from a tighter grip than do cast.
With two-die sets used
with bottleneck cartridges, things change again. When shooting cast bullets, it is common
to add an intermediate die that expands the case neck and bells the mouth. This is often
referred to as an M die. Here again, if youre using an M die, you dont need
the Lee. If youre not, and the neck grip of the sized case is acceptable, the
addition of the Lee die will aid bullet seating immeasurably.
Perhaps my favorite use
of the new Lee tool is this: With some of my bottleneck cartridges Ive been
employing a full-length sizing die with interchangeable neck bushings. I get to custom
control the amount of grip applied to the bullet and avoid using an expander button at
all. With cast bullets I control the neck grip on the bullet with my choice of bushing and
bell the case mouth with the Lee Universal Case Expanding Die. And I dont need to
buy an M die either. Bullet seating is greatly facilitated and the seating die returns the
case mouth to normal, and even applies a crimp if desired.
You may even have a few
uses of your own. Regardless, the new Lee Universal Case Expanding Die has earned a place
on my bench. - R.H. VanDenburg, Jr.