AutoMag Loading & Case forming dies




By J. Waters


Die stack 357 AMP
Taper Crimp

357 AMP
3 Die Set

357 AMP
3 Die Set

357 AMP
Case Form

44 AMP
Taper Crimp

44 AMP
4 Die Set?

44 AMP
4 Die Set

44 AMP
4 Die Set

44 AMP
Case Form

44 AMP
Case Form

44 AMP
Case Form

44 AMP
3 Die Set

45 Magnum
4 Die Set

Background: I wanted to create a page that would give the Automag Owner/Collector a guide to many of the loading dies that are/were made for the Automag. I am a fairly new Automag owner, and really didn’t have a clue as far as the Loading Dies went when I got my Automag. I have found that purchasing used dies can be tricky as many are missing parts, etc., and often the seller doesn’t really know what they have. Outline: There are many types of dies, as you can see on the picture on the left. I intend to talk about the dies themselves, which ones should be in what set, but this is not a reloading primer or manual. I’ll cover the straight wall cases first (44 AMP and 45 Magnum (Winchester Magnum)), then the bottleneck cases (357 AMP, but should apply to 22 LMP, 25 LMP, 30 LMP, 41 JMP, or other bottleneck cartridges), and finally, case forming dies. This focus is mainly RCBS made dies, as that’s what a majority of the Automag dies are that I have come across. Also included is the current, affordable Hornady offering in 44 AMP.Evolution:

This may sound a little strange but loading dies have gone through an evolution over the years and are not the same as they were 30 years ago. While the basic comcept is the same, some changes have been made, particularly of note to accomodate progressive loading machines. I’ll try to point those out along the way.

Types of Die Sets:

3 Die Sets typically consist of a Sizing Die, Expander Die, and a Seat/Crimp Die.

4 Die Sets typically consist of a Sizing Die, Expander Die, Seat Die, anc a Crimp Die.
-Note that the decapping unit may be located in either the Size Die, or the Expander Die.

Case Form Sets consist of a Form/Trim Die, Reamer Die w/Reamer, and should include an extended shellholder.


Straight Wall Automag

44 Auto Magnum (44 AMP)
Above is
pictured a 44 AMP RCBS 4 Die Set, RCBS Part # 19226. 44ampcomp.jpg
This is a
comparision of a 1972 RCBS set to a 1975/76 RCBS set.  Note the different
knurling height on the die sets (no effect on functionality).  The dies are
pictured from L to R:  Size, Expand/Decap, Seat, Crimp.44ampsize2.jpg44ampsize2.jpg44ampseat2.jpg44amptcrimp2.jpg Pictured above is the markings on the top of
each die.  Early dies have the date stamped on them like “75”, seen
here.  The Expander doesn’t have a date.  Later, RCBS went to a
“Letter” system to date dies (A, B, C, etc. each represent a year).

Notice the expander
on the left with integrated decapper, the decapping pin is held by a collet
machined into the end of the expander assembly.  The decapping pin on this
era die is “straight”, no “head”.  RCBS changed to a headed pin sometime in
the 1990’s.


Hornady 44 AMP
die set, current manufacture (as of 2002), Part # 544545.

picture of Hornady Die Set.  Hornady uses a floating decapper in the size
die, the expander is fixed and cannot be unscrewed.  The seater is a
floating unit that guides the bullet nose all the way up, and then seats and
crimps.  Currently the best bargain for the new Automag owner having
difficulty locating an original set.

Winchester Magnum (45 WIN MAG)



above is a RCBS 4 die set for the 45 Winchester Magnum.  I thought it was
worth mentioning as a few hundred were chambered for this cartridge in the
1980’s.  Notice the “55000” part number from RCBS, this is used to denote a
Custom Die Set.  The dies are as follows:  size/decap, expander,
seater, and crimper.  They are simliar to the 44 AMP 4 die set.  This
set happens to have “split” aluminum lock rings, the best type, as they cinch
down around the dies, instead of using the brass screw into the threads.

Necked Automag

 357Auto Magnum (357 AMP)


a common 357 AMP Die Set, RCBS Part #  35505, the tapered Automag
cartridges used a 3 die set: Size Die, Expander/Decapper, and Sear/Crimp Die.

To expand
on the above, this shows some variation.  Notice the Decap assembly
available for the size die.  This came about in the late 1970’s, early
1980’s for RCBS.  This allowed use in progressive reloading machines such
as the Dillon which require decapping in the sizing stage.  Notice the two
expanders-  The first is the traditional expand/decap assembly, the second
is only and expander.  Is is common to find the collet damaged/broken on
this era die sets, rendering it useless for decapping.  One option is to
purchase the decapper unit for the size die, and cut off the expander decap
collet and make the die only an expander.  Also, note that any 357 Magnum
Expander will work, and used die sets of 357 Magnum can be readily purchased to
acquire an original expander/decapper.


is a 1990’s 357 AMP dies set, RCBS Part # 56424 (notice the different part
number).  Notice the decap assembly is in size die.  The expander does
not have the decapper.  Notice the hexagon lock nuts with brass set
screws.  The lock nuts are small enough to use on tightly crowded
progressive machines (The older larger knurled lock nuts are too close for many
machines).  RCBS recommends placing a lead shot under the brass set screw
to avoid damage.  Black oxide coating on certain parts.

This is a 357
AMP Taper Crimp Die, RCBS Part # 55000 (custom die).  Lee Jurras advertised
these in his Newsletter’s.  The 357 AMP headspaces on the shoulder, so a
taper crimp so not be as critical, however, this die was offered in limited
quantity.  I have also heard of people using 150gr 35 caliber spitzer
bullets (loaded singly) for hunting, possibly using this die.

I don’t
have any info on other necked calibers, but die sets should basically be the
same as the 357 AMP.

Forming Dies

44 Auto
Magnum (44 AMP) from 30-06 Springfield or 308


Complete 44 AMP Case forming set, RCBS Part # 40039
(sometimes # 55000 was used).  On left, Reamer Die w/ Reamer, on right top,
RCBS extended shell holder #3 for case trimming, on right bottom form/trim
die.  Note Reamer is still in original protective coating.


are both RCBS case forming dies (On left, #40039, On right # 55000).  I put
this picture to show the difference in manufacturing.  The reamer die on
the left is taller than the right. The reamers are the same length, but note the
stop collar on the left is higher than the one on the right.  RCBS preset
the stop collar from the factory and recommended it never be adjusted. 
Also, this picture shows a good comparison of the die lock rings, set screw on
left (with lead shot underneath, unseen), and split lock ring on the right.

Case forming set from CH4D.  Reamer
does not come with stop.  CH4D provides custom dies at reasonable prices
for many obsolete/rare/wildcat calibers. 

Auto Magnum (357 AMP) from 308 Winchester


AMP Case forming set, RCBS Part # 40040 (sometimes # 55000 was used, shown
here).  On left,
on right reamer sie with reamer.  No extended shell holder, could be
missing or not ordered.  Note Reamer has no stop, as the case is necked
down before reaming and is reamed straight through.  With Starline 44 AMP
brass, one does not need this case form set, simply reform the brass in the 357
AMP sizing die. 

357 AMP case form set was recommended to use with 308 Winchester Brass, and did
not include 30-06 Springfiled as an option.  I do not know why this is,
maybe someone else can shed some more light on this.

on all reamer dies, all parts could be ordered seperately, and it is possible to
come across where someone has only a few pieces of the set.



1970’s RCBS Die Box, common for most Automag Dies

to current RCBS Die Box, may not say “Omark”, depending on era.  Newer
carbide die boxes are grey.

Interesting Facts from the 1972
and 1976 RCBS Catalogs



Die Set  RCBS Part Number  1972 Price  1976 Price 
357 AMP Loading Dies,
3 Die Set
35505 n/a 19.50
44 AMP Loading Dies
(SWC), 4 Die Set
19226 22.50 24.00
44 AMP Loading Dies
(WC), 4 Die Set
19227 22.50 24.00
357 AMP Case Form 40040 n/a 28.50
44 AMP Case Form 40039 27.00 28.50

1972, the dies cost no more than other similiar dies (ie, 44 Remington
Magnum).  In 1976, the 44 AMP carried a $1.50 premium due to the Taper