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There are many wonderful books and articles available on the Internet which
provide detailed instructions on how to properly prepare your cases for
consistent and accurate reloading. Paul Matthews’ series of books on Black
Powder Cartridge shooting and loading are an excellent source of information for
all BPCR shooters.
In the following text I have tried to address items that you probably (for the
most part) have not seen discussed in any of these series of books.
Problems With New Brass
In my opinion new brass is being sold too short to be useful in BPCR chambers.
An example is a popular case manufacturer that makes:
• New .45-90 brass cases which should measure 2.4” that actually measure from
2.389” to 2.393” in length before fire forming, and
• New .45-100 brass cases which should measure 2.6” that actually measure 2.589”
to 2.593”, with an occasional 2.595”.
It is also important to remember that you will loose .005” the first firing
and an additional .005” on subsequent firings for a total of .010”, making the
brass too short for the chamber in most rifles.
Have you ever noticed the lube ring on the mouth of your cases, especially in
cold weather? It may be an indication that the case is too short for the chamber
and the excess lube has now occupied that space.
Determining The Proper Length Cartridge Case For Your Rifle
You can get a pretty good idea of your chamber’s internal dimensions by
gradually trimming down a case that’s too long to fit your chamber properly
until the breech block closes without force, and the mouth of the case remains
sharp and is not crimped in.
An example would be to use a .45-100 case gradually trimmed down to determine
the proper length for a .45-90 chamber, or a .45-90 case trimmed down for a
.45-70 chamber, prior to fire forming. This method is not as accurate as a
chamber cast but we are trying to keep it simple for the new shooter.
Tight Chambers
Now I know some of you are saying, “Well -- I have a tight chamber and my brass
does not loose .010” with successive firings”. That’s a good thing, but
typically isn’t the case for the vast majority of BPCR shooters who are using
off-the-shelf or mass produced BPCR rifles in which the chambers are cut with a
factory reamer. Many of us either do not have or cannot afford custom-made
rifles whose chambers have been cut with a custom reamer. Remember, this
site is oriented toward the new BPCR Long Range shooter who is probably going to
be using a non-custom rifle.
Case Re-Sizing
I don’t recommend re-sizing (straight wall) cases once they are fire-formed,
either partial sizing with a full length die or using a neck only die. Strive to
“index” your cases when fire-forming them by using a symbol (you could use a
letter or star that is stamped on the back of the case) as an index mark. Insert
the case into your chamber every time that you load a round with that index mark
in the 12 o’clock position for the remainder of its useful life. By not re-sizing
the case:
a) we are allowing the case to maintain the closest tolerance possible for
the chamber in which it was fired,
b) we are eliminating the process of re-sizing the case and then expanding the
neck to allow seating the bullet, which can alter the concentricity of the
case/chamber relationship,
c) we are eliminating the need to use a seating die to place the bullet in the
case, as the bullet can now be hand seated.
By re-sizing the case and expanding the neck, we also alter the shape of the
case and increase the space between the sides of the case and the chamber walls.
The whole idea of fire-forming is to get a case to fit your chamber. Assuming
the case wall thickness is uniform, we would not want to change the
concentricity of the case in relationship to the chamber.
Neck Tension
Those of you who are familiar with high power or modern reloading techniques for
competition or hunting will recognize the term “neck tension”. Neck tension is
the pressure exerted on the neck of the case in order to a) hold the bullet in
place, and b) to get the proper ignition from the smokeless powder used in modern
ammunition.
This is important with many modern repeating rifles which are magazine fed and
where the overall length of the cartridge is critical for the firearm to operate
and feed reliably.
Neck tension in the world of the Black Powder Cartridge shooter is much
different. Paul Matthews presents an excellent discussion about neck tension in
his latest book entitled “Black Powder, Pig Lead and Steel Silhouettes”.
Chapter 9 is entitled “Neck Tension-How Little?”. Paul discusses a number
of factors concerning the reasons for and against neck tension as it pertains to
BPCR shooting
Based upon my experience, I prefer to use no neck tension when I reload for
competition. I firmly believe that having no neck tension produces the most
consistent ammunition possible because it is far easier to control no tension on
the neck of the case than to control how much neck tension.
Neck Wall Thickness
As far as neck wall thickness is concerned, a variance of .0015 or less is a
good number for which to shoot. I’m not going to get into neck turning or rim
thickness uniforming at this time, but they are factors that do affect overall
accuracy. New shooters should not be concerned with this element of reloading
when there are so many other things that must be mastered first.
Chamfering The Case Mouth
The mouth of the case should also be chamfered to remove any ragged edges
resulting from trimming the cases to a uniform length. I have recently begun
using a 14-degree chamfering tool made by Lyman for use with modern VLD (Very
Low Drag) bullets. I have found that this tool and the resulting 14 degree angle
that it puts on the mouth of the case makes seating the flat base BPCR bullets
that we use in Long Range BPCR easier to seat with virtually no likelihood of
shaving off any lead from the bullet.
Case Cleaning
For years shooters have used various types of media (i.e. crushed walnut hulls,
ground corn cobs, rice, etc…) to clean their cases (usually in a vibratory
polisher) after shooting. Recently, ceramic media has revolutionized the process
of straight wall case cleaning by eliminating the need for multiple cleaning
passes while delivering superior results (i.e. cleaning the primer pocket).
I recommend using a rotary tumbler like the Thumbler’s Tumbler (available from
Cabela’s) or the RCBS Sidewinder Tumbler for use with ceramic media. The ceramic
media is combined with water and a cleaning solution following the supplier’s
instructions. Tumbling your brass from 4-8 hours is usually all it takes,
depending on the number of cases you place in the tumbler with the media and
water solution.
Yes, some shooters use ceramic media in a vibratory polisher, but these units
are generally not approved by their respective manufacturers for use with wet
media. Using ceramic media in a vibratory polisher could create an electrical
hazard if it develops a leak and ruins the motor, voiding the warranty.
Pre-Cleaning Cases
Although ceramic media does an outstanding job of cleaning BPCR cases, I would
still recommend that you pre-clean your brass, using water and “Dawn”
dishwashing detergent. I use a small nylon brush mounted in a BATTERY
operated drill to remove the majority of the internal fouling before tumbling my
cases in ceramic media. DO NOT USE A CONVENTIONAL ELECTRIC DRILL FOR THIS
PURPOSE. DOING SO MAY RESULT IN AN ELECTRICAL SHOCK AND WILL DEFINITELY RUIN
YOUR DAY!
By George Liotta
Copyright© 2010 All Rights Reserved.
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