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ALL .40-65 WINCHESTER RELOADING DIE SETS
ARE NOT EQUAL
By Wayne McLerran
Posted 1/21/18

There are several well-known firearm reloading die manufacturers.  
Those that come to mind include: RCBS, Lyman, Lee Precision,
Redding, Hornady and Forster.  Unfortunately, due to slight
differences in chamber and bore dimensions of rifles, some brands of .
40-65 Winchester die sets may not be compatible with your rifle.

To better understand why there can be differences in die dimensions
you must understand that the .40-65 Winchester is not a SAAMI
standard cartridge.  SAAMI (Sporting Arms and Ammunition
Manufacturing Institute) is anassociation of the nation’s major
manufacturers of sporting firearms, ammunition and components.  
SAAMI is also an accredited standards developer for ANSI (American
National Standards Institute) and is actively involved in setting
industry standards and coordination of technical data.  Although it’s
not
mandatory that firearm manufacturers adhere to the SAAMI
standards, it is in their best interest to do so, especially those that
are a SAAMI association member.  SAAMI considers the .40-65 Win. an
obsolete cartridge.  Therefore, firearm manufacturers have
somewhat of a “free hand” in defining the chamber and throat
dimensions, and die manufacturers have to match the chamber
dimensions to sell dies.

I purchased a Browning .40-65 BPC rifle shortly after they were
introduced in 1996.  After making a CerroSafe chamber cast, which I
do with most all rifles I plan to shoot, especially those for black
powder cartridges, I checked with several suppliers prior to ordering
a set of dies.  At the time Lyman indicated their 3-die set was
designed to match the Browning chamber which has a well-defined
(constant diameter) 0.5” long neck.  Since then I’ve happily loaded
many thousands of rounds using the Lyman dies, later adding a Lyman
neck-only resizing die as a means to improve accuracy and increase
case life.

The Browning BPCR has a “generous” chamber with a 0.436”
diameter neck, resulting in a fire-formed 0.435” outside diameter
case neck.  Therefore, the fire-formed case must be at least neck
resized then expanded to the correct diameter to hold even a “finger-
seated” 0.410” diameter bullet.  To eliminate having to neck resize
and then expand fire-formed cases, and using Starline brass with a
case neck wall thickness of 0.011”, one could have a custom mould
made for a 0.412” diameter bullet.  But unless the 1st couple of
driving bands are reduced in diameter, the bullet will not slide into
the 0.410” to 0.411” diameter extended freebore, common to the
Browning .40-65 throat, and contact the leade.  I’m seriously
considering this approach and will likely have a custom bullet mould
made.

A few months ago a Browning owner emailed me regarding reloading
for his .40-65 BPCR.  Attempting to save a few dollars over the more
expensive dies, he’d purchased a set of Lee Precision .40-65 dies.  
The dies were well made but would not work for the Browning.  After
full-length resizing the cases, the expander and seating dies would
not accept 0.408” to 0.410” diameter bullets, the typical diameter
range for bullets used in the Browning.  The bullets would not even
feed into the seating die.  It turns out the dies were designed for
0.406” diameter bullets for “cowboy rifles”.  Given credit to the
company, Lee offered to enlarge the diameter of the expander die
and ream out the seating die to handle up to 0.412” diameter bullets,
but by then the gentleman had purchased a Lyman die set.

At the March 2017 Texas State BPCR match, I was fortunate to win a
substantial gift certificate towards a Shiloh Sharps rifle.  Several
months later the new rifle arrived - a very nice 1874 #1 Sporter
cambered for the .40-65 Winchester cartridge.  Being eager to try
out the rifle, a few Remington cases, already reformed from .45-70,
were quickly full-length resized and neck expanded with the Lyman
dies only to find out the cases would not fully chamber in the Sharps.  
To identify where the case was contacting the chamber, the brass
was coated with blue machinist die (a felt-tip black marker will also
work in a pinch).  It turns out the Lyman resized case diameter in
front of the web (just forward of the rim) was the problem area,
being slightly larger than the Sharps chamber.  One option is slightly
shortening the Lyman full-length resizing die, tapering and polishing
the inside lip, resulting in additional resizing of the brass.  But I
remembered I have a RCBS .40-65 die set that came with a rifle
purchased for resale.  Fortunately I’d procrastinated in selling the die
set on GunBroker or eBay.  The RCBS dies, which are designed for the
Shiloh Sharps chamber and 0.408” groove diameter bore, worked
perfectly.

Although I have Redding and Hornady dies for handguns and other
rifles, I have no experience with .40-65 dies from Redding, Hornady
or Forster.  I do suggest contacting your favorite reloading die
supplier and at least questioning if their .40-65 dies are compatible
with 0.409” to 0.410” diameter bullets.  Also, as mentioned above, I
highly recommend the 1st thing you do with a rifle you have yet to
reload for is make a chamber cast or impact impression of the
chamber and throat.  The chamber and throat dimensions will better
prepared you to have an intelligent conversation with a technical
representative of the die supplier.  Besides helping select a die set, a
cast or impression will provide all the dimensions required for
reloading ammunition for your rifle.  If you’re unfamiliar with making
a chamber cast or impact impression go to the article titled
Chamber
Casts and Impact Impressions.

Wishing you great shooting,
Wayne