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BULLET DESIGN & LOADING SPECIFICATIONS
FOR THE BROWNING .40-65 BPCR
By Wayne McLerran
Updated 12/2/17

The .40-65 Winchester cartridge is arguably 2nd only in popularity to the .45-70
Government for silhouette competition.  Approximately 1300 BPC rifles in
caliber .40-65 were manufactured by Miroku for Browning.  The rifles are
popular and are common in matches around the country.  The .40-65 is my
preferred silhouette caliber.  My experiences with the .40-65 Winchester
cartridge in the Browning BPCR are the basis for this article.  I will cover the
results of testing four well-known bullets and give you some ideas why I
decided to design a custom bullet for the rifle.  Also discussed is the only bullet
design software I’m aware of and design considerations I feel are important
when designing a bullet.

Without a doubt a couple of the key factors in loading accurate ammo includes
knowing the chamber and bore dimensions of your rifle along with a basic
understanding of the pros and cons of various bullet designs.  The chamber and
bore of the Browning BPCRs are very consistent from rifle-to-rifle but there are
slight differences which can only be determined by making a cast or impact
impression of the chamber and throat of your rifle.  Also helpful is an
elementary knowledge of internal and external ballistics.  I don’t profess to be
an expert in any of these areas but have experimented with a few bullets and
formed some opinions why some may be better suited than others for the
Browning.  Other factors that affect bullet design and selection include the type
of bore conditioning techniques used.  For example, will you be blow-tubing or
wiping between shots?

Mould Suppliers
There are several custom mould manufacturers that will “cut” a mould to your
specification.  A partial list includes Hoch Custom Bullet Moulds, Accurate
Molds, Brooks Tru-Bore Moulds, Buffalo Arms Co. (BACO), Sagebrush
Products, Fred Leeth/Pioneer Products, Old West Bullet Molds, Boomers Bullet
Moulds, KAL Tool & Die, NEI Handtools and Mountain Molds.  Custom
moulds range in price from $100 to $200, generally more than $150 for a high-
quality single cavity mould without handles.  BACO and several of the custom
suppliers also sell “semi-custom” high-end moulds.  Paul Jones (Paul Jones
Precision Moulds), arguably the most well known of the custom suppliers, has
retired.

A better option for a new shooter may be a “cataloged” (off-the-shelf) mould
until you’re convinced that BPCR shooting is for you.  Redding/SAECO, RCBS
and Lyman make a line of good quality moulds in a price range of $70 to $90.  
Although the dimensions may vary slightly from mould to mould they will
generally be sufficient to get started.  Some experienced shooters continue to
use moulds from these manufacturers with excellent results.  If an off-the-shelf
mould results in excellent accuracy, there’s little or no reason to change.  As
you will find in the following discussion, the off-the-shelf and semi-custom
moulds I’ve tried so far, which were recommended for a Browning by others,
did not work out as well as I would have liked.  But there are many
moulds/bullets available that can be used in a .40-65 cartridge.  I’m just not
willing to spend more time attempting to find one and decided a custom mould
is the solution for me.

If you’ve made the decision to purchase a custom mould, the manufacturer will
need as much information as possible.  Most mould manufacturers list ordering
requirements on their websites.  The ideal information includes a drawing with
precise dimensions, expected bullet weight and alloy used.  But many new
BPCR shooters only have a general idea what they want, hence the earlier
recommendation of starting with an off-the-shelf mould.

In lieu of supplying a detailed drawing, the mould manufacturer can make an
educated recommendation but will need some dimensions of the chamber and
throat along with the groove and bore (land) diameters.  Sending a chamber cast,
impact impression or lead slug made by “slugging” the bore will also help but
may not be necessary if precise measurements are provided from the cast or
impression.

Prior to designing a custom mould, I tested four bullets that were suggested by
shooters for the Browning .40-65.  All are bore-riding designs, aiding in nose-to-
bore alignment, and is discussed in further detail in the section titled, Nose
Design.  They were hand seated in the case with the case lip slightly flared
(belled), making bullet insertion easier.  The flair was not removed; helping to
ensure the rear of the bullet is centered in the chamber.  Following are the
results.

Shooting Test Results

















Figure 1: (L to R), BACO JIM409400M4 “Money Bullet”, Lyman Snover
410663, Paul Jones 40001 Creedmoor, SAECO 740


As displayed in Figure 1, the following bullets were tested: BACO’s
JIM409400M4 “Money Bullet”, Lyman Snover 410663, Paul Jones 40001
Creedmoor and SAECO 740.  16:1 alloy was used for the BACO Money Bullet
and Lyman Snover, 25:1 with the Paul Jones Creedmoor and SAECO 740.  The
cartridge overall length (COAL) was determined with the bullets seated to
contact the leade.  Once the COAL was determined, each bullet was loaded with
a range of powder amounts in one grain increments starting at approximately
zero compression up to 0.250” of compression depending on the bullet design.  
Swiss 1.5Fg, 0.060” over-powder wad, White Lightning lube and Remington 2-
1/2 (large pistol) and Winchester WLP (large pistol) primers were used.

Since a blow tube was used, with the exception of the SAECO 740, 10
cartridges plus 2 for fouling the bore were loaded for each powder increment
and fired at 200 yd. at separate poster board targets using bench mounted cross
sticks.  The average velocity, extreme velocity spread and standard deviation
was recorded for each shot.  Subsequently, each bullet hole was closed and
taped from the back of the targets in order to inspect for signs of bullet tipping.  
With vertical spread being the main selection criteria, the best load was selected
for each bullet.  See Figures 2 thru 5.  Note that the vertical spread of all were
approximately 1MOA (2”) or better at 200 yds.


















Figure 2

















Figure3
















Figure 4

















Figure 5

Next, after 2 shots to foul the bore, 10 cartridges of the selected loads were
fired at 500 meter poster boards with ram size targets.  See the results below.  
During all testing, the bore was cleaned after each 12-shot string.  Needless to
say, testing required many hours of loading and shooting.  A total of 600
cartridges were fired during seven sessions at the range.  Including target
evaluations and documenting the results, approximately 70 hours was required
to complete the exercise in addition to 35 lbs. of alloy, over 5 lbs. of powder,
600 primers and wads.

500 Meter Results

SAECO 740:
The results were poor with only 2 out of 10 bullets hitting the target.  I attributed
the poor showing to a combination of the short length and lighter weight coupled
with the marginal aerodynamic nose design, believing the bullet became
unstable as the velocity dropped due to the high drag nose.  Also, the mould was
slightly out of round.  The driving band (body band and base band) diameters
varied by 0.003” as the bullet was rotated.  Or it may just be that the bullet is
too short for the Browning 16:1 twist rate.  Regardless, I’m not planning on
spending additional time and effort to figure it out.

Lyman Snover 410663:
The Lyman Snover loads were a little better with 5 out of 10 bullets hitting the
target.  The relatively poor results were most likely due to inadequate lube
capacity for the warm (95 degrees) shooting conditions.  No muzzle lube star
was evident afterwards.  The bullet has a good reputation when used in the
Browning, so I may retest the bullet when wiping between shoots.  The Lyman
tends to shoot well if bore fouling is controlled by favorable shooting conditions
(mild temperatures and relatively high humidity) or wiping between shoots.

Paul Jones 40001 Creedmoor:
The results were good with all shoots hitting the target within a 12” vertical
spread.  Although the nose shape is very similar to the SAECO 740, it holds up
better than the SAECO at longer distance due, in my estimation, to the longer
length and additional weight.  Also, it carries plenty of lube for blow tubing in
the hot and dry central Texas summer conditions.  By the way, since Paul Jones
has retired, if you’re interested in trying his 40001 Creedmoor bullet design,
Steve Brooks (Brooks TRU-BORE Bullet Moulds), the well-known custom
mould manufacturer, offers a mould for the identical bullet.

BACO JIM409400M4 Money Bullet:
The BACO Money Bullet results were excellent with all shoots hitting within a
10” vertical spread.  I really like the aerodynamic nose design resulting in
increased velocity and flatter shooting characteristics.  The BACO design has
the 1st three body bands (includes the nose band) reduced with the remaining
four bands at 0.409” (includes the base band).  Therefore, in order for the bullet
to contact the leade for alignment, the bullet seating depth is only 0.200”.  And a
minimum of 69grs of powder is required to fill the case with a 0.060” wad,
resulting in a velocity of 1345 fps.  Although it performed admirably, it’s my
belief that with all driving bands the same (0.409” to 0.410”) diameter, and with
deeper lube grooves, the bullet could be accurately loaded with less powder and
fewer exposed lube grooves and “stand up” better in the central Texas summer
heat.  Although the muzzle lube star was thin, the bullet held sufficient lube
during the tests, but the worse testing condition was a very humid 95 degrees.  
Based on the lube capacity I would not be surprised to find that it “runs out of
lube” as the temperature approaches 100 degrees and the humidity drops to 30%
or so.

Design Software
The aerodynamic benefits of various nose designs and the overall design of a
cast bullet is a subject on which I’m certainly not an expert.  What little I do
know is likely just enough to get me into trouble.  Therefore I must rely heavily
on the knowledge and experience of others.  I will suggest that if you are
considering a custom mould made to your specifications, one of the quickest
ways to come up to speed on the various aspects of bullet design and develop a
basic understanding of the pros and cons of a variety of shapes and dimensions
is to purchase a cast-bullet design software program.

There are numerous programs available that will provide exterior ballistic data
on the flight of a bullet once the bullet characteristics are defined.  Many are
free or can be downloaded for a nominal fee.  But finding an affordable good
bullet design program is another story.  Researching what is available results in
either expensive computer intensive programs for military projectile design or
very basic limited programs offered by bullet suppliers or bullet equipment
manufacturers.  The only affordable, comprehensive cast-bullet design software
programs that I’m aware of are sold by TMT Enterprises (http://www.tmtpages.
com/).  Three programs are available: Basic, Advance and Professional, and an
Ultimate Companion Module.  Once the bullet design is completed the software
provides a bullet specification file (see Figure 6) ready to send to a custom
mould manufacturer.  TMT Enterprises’ website will give you a good overview
of the program capabilities.  Considering the cost of moulds, reloading supplies
and time spent finding an accurate bullet, the programs are relatively
inexpensive.
Note – Keep in mind, to successfully design a bullet that closely fits a chamber
and bore, a chamber cast or impact impression and bore slug will be required to
determine the chamber, throat and bore dimensions of your firearm.




















Figure 6: Typical .40 Caliber Money Bullet Specification

Figure 7 is the results of using the Ultimate Companion Module to overlay the
images of the case and bullet over the chamber.  Since Browning designed the
throat of the .40-65 BPCR with a freebore diameter 0.002” larger than the
groove diameter, TMT’s software identifies the transition from freebore
diameter to grove diameter as the freebore leade.  Also note the throat includes
the freebore, freebore leade and leade, and the chamber transition step is
included in the freebore length.

















Figure 7: Browning .40-65 Chamber with Case & Money Bullet


Bullet Design Considerations
If you decide to have a custom mould made it’s definitely worth spending some
time researching and becoming familiar with the features and dimensions of a
bullet besides the diameter, weight and length.  The following are discussed in
more details below: bullet length, driving band diameters and contact lengths,
lube quantity and contact length, location of the lube grooves, nose design and
alloy mix.  Other design considerations include: tangent and secant nose shapes,
ogive radius, meplate diameter, center of pressure (C.P.) and center of gravity
(C.G.).

Bullet Length
A well-known bullet designer and shooter determined that the preferred bullet
length in the Browning is 1.375” to 1.400”.  One longer would potentially
become unstable in the 16-twist bore.  The four bullets displayed in Figure 1
have a length of 1.400” or less as noted below.  The SAECO #740 is the
shortest of the four and resulted in the worse accuracy in the 500 meter tests
detailed further on in this article.  Since others have reported success with the
bullet in 16-twist barrels the length may not be an issue.  There could have been
other reasons for the SAECO 740 poor showing.  Refer to additional comments
on the bullet under the section titled, Shooting Test Results.

Bullet Lengths:
BACO JIM409400M4:                1.400”
Lyman Snover:                            1.380”
Paul Jones Creedmoor:                1.375”
SAECO 740:                               1.320”

Driving Band Diameter
A common reloading technique to increase accuracy is selecting a bullet with
driving band diameters that can be used in un-resized fire-formed cases which fit
the chamber dimensions as close as possible.  But this is not feasible in the
Browning due to the generous chamber neck diameter averaging 0.436”.  Under
firing conditions the case neck outside diameter (OD) will expand to match the
chamber neck inside diameter (ID) and then shrink, generally 0.001” or so,
allowing for extraction.  The result is an average fire-formed case OD of
0.435”.  Assuming the case wall is 0.011” thick (0.022” inclusive) the diameter
of the ideal bullet driving bands would be 0.413” for slip fitting to 0.414” with
0.001” of tension.  But a bullet with either dimension is not a good idea because
the Browning freebore and groove diameters average 0.411” and 0.409”
respectively.

Besides the fact that the body bands will not fit into the freebore or throat, firing
a bullet 0.004” to 0.005” over groove diameter is risking accuracy problems.  
The chamber-to-throat transition step and bore will squeeze the bullet to a
smaller diameter, resulting in body band and base band fining (an irregular base)
which can have a negative effect on accuracy.  Additionally, if a bullet with
driving band diameters larger than 0.411” is used, the bullet must be seated
deeper in the case since it would be too large to slide into the freebore, resulting
in less powder capacity (limited velocity) and, depending on the nose design,
loss of nose alignment and support from the freebore, leade or bore.  Therefore,
a bullet with driving band diameters of 0.409” to 0.410” is the solution, which
means resizing the fire-formed case neck to a smaller diameter.

Driving Bands Contact Length
To hold sufficient lube when blow tubing BPCR bullets typically have several,
relatively long and deep, grease (lube) grooves separated by body bands.  
Therefore, while keeping in mind the required bullet length, weight, nose design
and total lube contact length, the bullet designer has to make a trade off of lube
groove lengths versus the lengths of the driving bands (body bands and base
band).  Another consideration is lead fouling tends to be directly proportional to
the length of the driving bands.  The longer the bands the more “bearing surface”
contacts the bore, increasing the possibility of bore leading.  Realistically,
0.025” is likely the lower limit of a body band length.  Many common bullet
designs feature body band lengths of 0.050” to 0.060” with a few approaching
0.100”.

The base band length is another consideration.  Since gas-check bullets are not
allowed in sanctioned NRA silhouette matches, BPCR bullets must have a base
band designed to handle the high pressures of expanding powder gases and
prevent or minimize gas blow-by while retaining its shape, which is critical to
maximizing accuracy.  Therefore, the base band is typically longer than the body
bands, significantly more so in some designs.  In lieu of having no analytical
data to support a specific length or range of lengths, I use the base band design
of several successful bullets, which have lengths ranging from 0.075” to 0.100”.

Lube Quantity & Contact Length
When wiping between shots, lube volume is less of a concern and the lube
grooves can be relatively shallow.  In fact some shooters that wipe between
shots have reported success with bullets without lube grooves.  The bullets were
cast or swaged with a rough surface and dipped in lube.  But when using a blow
tube, not only must the bullet carry sufficient lubricant to coat the bore to the
muzzle to eliminate leading, the lube is also essential in helping to keep the
powder fouling soft from shot-to-shot; especially in hot and dry condition.  Two
factors are important when designing lube grooves: volume and contact length.  
Adding up the length of the lube grooves determines the lube contact length.  A
well-known bullet designer and shooter found through rigorous testing that
0.250” of lube contact length is the minimum necessary for blow tubing.  The
length and depth of the grooves determines the lube volume or carrying
capacity.  Although the lube contact length may be adequate, if the grooves are
not deep enough to carry sufficient volume the bullet may run out of lube prior
to reaching the muzzle.  A good method to determine if the bullet holds enough
lube is to check the muzzle for a lube star, lack of which indicates insufficient
capacity or possibly poor quality lube.  But the presence of a lube star does not
indicate adequate contact length.  For example, if the lube grooves were deep
but very short the lube quantity may be sufficient but much of it would not be
available to lubricate the bore and would be thrown out of the grooves as the
bullet exits the muzzle, creating a lube star.

A good example of marginal, I consider it inadequate, contact length and
insufficient lube quantity when using a blow tube is the Lyman Snover with a
contact length of 0.200" and lube capacity of only 1 grain.  It's a nice looking
bullet with an aerodynamic nose design, and under the right conditions it can be
very accurate, but when the ambient temperature increases and the humidity
drops the shallow lube grooves can become a liability when blow tubing.

Listed below are the total lube contact lengths and lube capacities (weight in
grains) and volume (in cubic centimeters) of the four bullets in Figure 1.
Paul Jones Creedmoor:                0.340”, 2.2gr, 0.15cc
BACO JIM409400M4:                0.250”, 1.5gr, 0.11cc
SAECO 740:                               0.300”, 1.4gr, 0.10cc
Lyman Snover:                            0.200”, 1.0gr, 0.07cc

Location of the Lube Grooves
Another design consideration concerning lube grooves is the location of the
grooves.  Note that one of the lube grooves in Figure 7 is located directly under
the chamber transition step, which is a good practice when loading BPCR
ammo.  As the relatively soft bullet obturates (expands under pressure), unless
prevented by lube, lead will fill the transition step and may be smeared back
along the driving bands or remain in the chamber step as a lead ring.  Both can
have a negative effect on accuracy.  The ideal configuration places a lube
groove under the transition step when the bullet is seated at the preferred seating
depth.  Should you prefer that the bullet contact the leade to aid alignment, then
the dimensions from the contact point to the transition step should be determined
and used to define the location of a lube groove, which is easier said than done
even with accurate chamber and throat dimensions.

Nose Design
As mentioned in the Design Software section, I don’t know enough about the
aerodynamic benefits of various nose designs to discuss the subject intelligently
other than noting that the Money Bullet nose design is very aerodynamic,
resulting in a bullet with a high ballistic coefficient.  And based on bullet tipping
tests it holds up better (more stable) at longer distances than other nose designs
I’ve tried in the Browning.  My hats off to the late Dan Theodore for
popularizing the “Money Bullet” design.

Concerning bullet alignment, it should not come as a surprise to anyone that it’s
one of the most important factors affecting accuracy.  One method to ensure
nose alignment of a cast bullet with a nose larger than the bore is to force the
nose into hard contact with the leade.  Another technique is to use a bullet with
a bore-riding nose design with a nose diameter that closely matches the bore
diameter.

When starting BPCR shooting I choose to go with a bore-riding nose design
simply because the Paul Jones #40001 bullet could be seated much further out
of the case, resulting in additional powder capacity and higher velocity.  At the
time I did not appreciate the alignment benefits of using a bore-riding design,
which allows the full length of the nose to slide into and ride (rest) on the bore.  
But to utilize the nose for alignment the diameter of a portion of the nose must
matched the bore (land) diameter as close as possible and still slide into a
fouled bore with minimum resistance.  When using a blow tube, a nose diameter
of 0.001” less than the bore (land) diameter is usually sufficient to allow for
fouling.  If the nose diameter is significantly smaller than the bore, alignment
will be compromised even with adequate obturation (bullet expansion).  In that
case it helps if the 1st body band wider than the nose is forced into firm contact
with the leade.  When wiping between shots the nose diameter can approach the
bore diameter since there is little or no fouling to interfere with the nose when
chambering a round.

Alloy Mix
Having limited experience with various alloys I don’t intend to make a
recommendation on the preferred mix for a specific bullet design other than to
pass along what has worked for me.  BPCR shooters have reported success with
relatively soft 30:1 (lead:tin) alloys to the harder 16:1, with some reporting that
wheel weight alloys, typically containing antimony, work well for them.  Having
accumulated around 1000 lbs. of wheel weight alloys, I plan on experimenting
with it in the future.

Some shooters use a softer alloy to ensure a loose fitting bullet expands
(obturates) quickly when fired to completely fill and align the bullet in the throat
and bore.  My definition of a loose fitting bullet is one that does not closely
match the throat and bore dimensions.  Others firmly believe that if a bullet with
a diameter smaller than the groove diameter is seated out to almost touch the
lands and is fired in a bore with an oversize freebore, it will obturate, filing the
freebore and self-align prior to being forced into the leade.  I disagree with these
approaches, firmly believing that a bullet out of alignment with the bore will not
be symmetrical after it obturates.  So what has worked for me so far?

It’s pretty simple.  For bullets such as BACO’s JIM409400M4 Money Bullet
and Lyman Snover 410663 with aerodynamic streamline noses with relatively
little nose-to-bore contact I use 16:1 alloy to eliminate the possibility of nose
slump since a substantial portion of the nose is not supported by the rifle bore.  
If the alloy is too soft the nose may slump resulting in an unbalance and
therefore unstable bullet, especially at longer distances.  But keep in mind that
when using a harder alloy it’s more important that the bullet dimensions closely
match the throat and bore dimensions in case the harder alloy does not
adequately obturate.  18:1 or 20:1 alloy may work just as well with these bullets
but I have not sufficiently experimented with either.

For bullets with a significant amount of nose-to-bore contact I’ve settled on 25:
1.  Examples are the Paul Jones 40001 Creedmoor and SAECO 740.  I tried 30:
1, 25:1 and 20:1 alloys with the Paul Jones mould and found no real benefit of
one over the other.  I believe it’s because the mould produces bullets with very
uniform dimensions that closely match the throat and bore of my rifle, and my
loading technique ensures chamber and bore alignment.

My Baseline Bullet Features & Dimensions

For Blow Tubing
When using a blow tube in central Texas summer conditions, the bullet will have
the following features and approximate dimensions: Length of 1.400”, diameters
of all driving bands (body bands and base band) of 0.410”, a 0.800” long
“Money Bullet” nose design with a diameter of 0.399” (to allow for fouling).  
The 5 lube grooves would be 0.060” long and 0.030” deep with a total lube
contact length of 0.300” and hold a minimum of 1.75grs of lube capacity.  The
bullet would have a base band length of 0.100”, four 0.050” long body bands
and weigh as close to 400grs as possible depending on alloy composition.

For Wiping Between Shots
When wiping between shots, since lube capacity is less critical and fouling
should not be a factor, an appropriate bullet would have the following features
and dimensions: length of 1.400”, diameter of all driving bands of 0.410”, a
0.800” long “Money Bullet” nose design with a diameter of 0.400”.  The base
band length would be 0.100”.  To increase the weight the two rear body bands
would have a length of 0.075” and the five lube grooves would be 0.050” long
and 0.025” deep and hold a minimum of 1gr of lube capacity.  The two forward
body bands would have a length of 0.050”.  The bullet will weigh as close to
410grs as possible depending on alloy composition.

=======================

After evaluation the four bullets pictured in figure 1 I decided to switch from
blow tubing to wiping between shots.  Not being satisfied with the four bullets
including BACO’s JIM409400M4 as discussed earlier, I requested BACO make
a mould to my Money Bullet design for wiping between shots.  BACO decided
to add it to their .40 caliber bullet mould selection as JIM410410M3.

Figure 8 is the specification I sent BACO, which they later listed on their
website as JIM410410M3.  If you’re wondering why TMT’s software was not
used to create the specification, it’s because I decided on two different body
band lengths to allow positioning one of the lube grooves under the chamber
transition step when loaded.  I don’t know if the current version of TMT’s
software will handle different body band lengths but the version I have will not.  

















Figure 8: Bullet Specification Submitted to BACO


Figure 9 is a photo of the actual JIM410410M3 bullet and cartridge loaded with
the bullet.  It may not be obvious but BACO made some minor changes.  The
bullet is close to the specification I sent with the following changes: the 1st lube
groove is slightly longer than the rest and the body bands are slightly longer than
I specified.  I expect that BACO “played” with the design to obtain the
requested weight.  It weighs 408grs with 16:1 alloy and right at 411grs with 20:1
alloy, which is what BACO used for the sample bullet shipped with the mould.  
The lube capacity is a little over 1.3grs.  After experimenting with the bullet I
prefer it over all the others I’ve tried so far.






















Figure 9: JIM410410M3 Bullet & Loaded Cartridge


Wishing you great shooting,
Wayne