I have always been at a loss as to why books and magazine
articles discuss elementary handloading techniques in a step by
step fashion but not the more intermediate or advanced methods.
The more advanced techniques I have seen are piecemeal and the
handloader must search through a mix of opinions and try to decide
for himself what works what is reloading equipment sales hype
and what is just someone's opinion . I have not seen several of
my techniques mentioned in books and magazines so I thought others
may be interested in them. I will try to explain why I do different
things so the user of this information can decide for himself
the logic or fallacy of my ways.
I start out with a bullet that I want to use either with
a hunting application in mind or with a match shooting application
in mind.
I then look through reloading manuals for a good powder to
start with . I find Sierra and Hornady loading manuals especially
beneficial because they have a table arrangement for the velocity
vs. Powder charge that lets you see at a glance what powders produce
the maximum velocities and how others compare. I have a tendency
of picking the faster powders that will produce the maximum velocity.
I have not seen this in any literature but because modern smokeless
powder burning rates are dependent on both temperature and pressure
to burn as intended, I feel that a more consistent and dependable
burning rate will be achieved in using one of the faster burning
powders, as they will build up to a higher pressure and temperature
thus giving the highest probability of complete and uniform burning.
This is my starting philosophy and has not always been shown to
work for the best. But I believe it is basically sound reasoning.
There is a second reason I tend to the faster powders, I
am now experimenting with Molybdenum Disulfide (MoS2 also known
as "MOLY") lubricant coatings on bullets and one of
the resulting characteristics is that pressures are typically
lowered. This reduction in temperature and pressure will affect
the burning characteristics in a way that I believe is similar
to using a slower powder. More will be discussed on this later.
At this point I can take several approaches to bullet seating:
1. First is to seat for normal functioning of the magazine
which in the case of typical rifles means the bullet has a considerable
amount of free bore and will probably deform itself somewhat when
it impacts the forcing cone where it enters the rifling.
2. second I can seat the bullet for 5 to 10 thousandths free
bore. This is what most reloaders do for maximum accuracy.
3. Third I can pre-load the bullet by seating for 5 to 10
thousandths inch setback. This will start the bullet right in
the forcing cone, reducing the possible damage as a result of
entering the forcing cone while moving at a high rate of speed.
You must keep in mind that the barrel friction of a bullet "in
motion" is considerably less than the barrel friction of
a bullet "at rest" . What this means is under normal
loading conditions as the pressure starts to rise the bullet starts
to move and enters the bore at some velocity, the bore to bullet
friction will be of some normal and expected value. This bore
to bullet friction holds the bullet back resulting in high but
expected chamber pressures. When pre-loading a bullet you are
setting up a condition where the bullet is pushed into the bore
during the closing of the bolt so the bullet slips back into its
case 5 to 10 thousandths of an inch. This means that the bore
to bullet friction is considerably higher and the pressure from
the burning powder will start to rise with the bullet STUCK in
the bore. As a result the bullet will not start to move until
the chamber pressure is considerably higher than normal. This
also means, under the higher pressure and the resulting higher
temperature of the burning powder, that there is even faster burning
of the powder compounding the higher pressure. The bullet will
no doubt start to move under this condition but it can only accelerate
so fast. If the bullet doesn't move down the bore fast enough
to increase the air space behind it for the burning gasses to
expand into, the pressure can go dangerously high. This is something
to take seriously when attempting to work up loads under the pre-load
condition. Remember if you don't have a warm feeling in your tummy
when you are ready to pull the trigger then don't. And if you
are not going to pull the trigger there is no point in making
the round. Remember what you have in your hand is a pipe bomb
with a lead plug in the end. The idea is to have the lead plug
blow out in a very controlled and repeatable fashion and not let
the pipe bomb explode!
In my 300 win mag. I must reduce the powder charge 10 to 12 percent
from normal loading conditions when I pre-load.. The resulting
increase in pressure due to pre-load will compensate for the reduction
in powder and its velocities will be about the same. Under this
pre-load condition, "for a given powder charge" I see
about a 300 ft per second increase in velocity of the bullet.
I have seen no sign of excess pressure on the brass or primer
under this pre-load condition, although I have always worked near
or below rated bullet velocities. But remember all guns have there
own personalities and start with a LOW load.
4. Fourth I can do any of the above with a bullet coated
with MOLLY. As I have just started using MOLY I will make a few
comments on this subject later.
At this point you must organize your approach to the actual
testing of variations of these loading possibilities, or you will
just be burning powder and throwing lead, with only a sore shoulder
to show for it. I came to the realization that a chronograph is
a must for a serious reloader. Without one you are loading to
high enough pressure to stretch the brass and primer out of shape
then downloading some amount hoping to be on the safe side. I
know most guns are made to withstand quite a bit more pressure
than they need to, but keep in mind that the bolt is just a holding
device for the back of the brass cartridge, "it doesn't seal
anything". Its the brass that expands out to the chamber
walls and seals the 50 or 60 thousand pounds per square inch pressures
of superheated gas that are a few inches in front of your face.
You don't want to push that brass too far!! Doing this testing
with several powders and possibly different primers and a variety
of bullets, while all the time trying to compare the results would
be an impossible task without a measuring device like a chronograph.
Without a chronograph the only information that you have to analyze
can't be much more detailed than group size. I don't think this
is a safe and efficient way to go at reloading. Start adding up
the cost of bullets, powder, primers, brass, your time and gas
to go to the range, and then think about after all this having
worked up the perfect load only to find out that you have worn
the barrel out with all the testing, and now you can start all
over again! Tests have shown that a high power rifle starts to
show its age after about 1,000 rounds.
With a chronograph you can start with a safe low load, fire
a couple of shots and plot the velocities on the vertical axis
of some graph paper (increased velocities going "up"
the side) with the corresponding powder charge on the horizontal
axis of the graph (with increased powder charges going "to
the right"). If the velocities are higher than expected reduce
the charge and try again and graph the results. In all probability
you will be able to increase the powder charge considerably as
the loading data has a considerable margin for safety and you
can see this immediately from the data points on the graph. From
these first few shots you will see a line forming through the
groups of velocity/powder charge points. Draw a straight line
through the average of each of these groups and you will have
a good estimation of what the velocity will be with any powder
charge, extend that line up to the velocity that the loading manuals
say should be maximum and you will have a good idea what powder
charge you are working toward. Keep in mind you may not quite
be able to make the rated velocity without signs of pressure so
work up slowly. With the exception of one hand gun I have found
the loading books are overly optimistic on their velocity vs.
powder predictions by one to two hundred feet per second. In other
words you will almost always have to add more powder than the
books say to achieve a given velocity. Record the temperature
that the ammunition is being fired at, this temperature has a
very definite effect on the rate the powder burns, and as a result
the velocity for a given amount of powder. The overall effect
of varying temperature is to move the line that you just drew
on the graph paper, up for increased temperature and down for
decreased temperature. With this in mind its important to chronograph
at all temperatures that you expect to shoot at. There will be
times when your ammunition may be cooking in the sun for hours
or you may be hunting at sub zero temperatures. Chronograph over
all these temperatures and draw a separate line in about 10 degree
increments so you can predict what the velocity range will be
at non tested temperatures. The variation in velocity with temperature
is not linear, at low temperatures the variation in velocity for
a given change in temperature is small but at the higher temperatures
velocity changes quickly with temperature and if you have a good
hunting load for winter applications and try to use this same
load some hot summer day it may give you a nasty surprise. With
this graph as a guide you now have some idea as to how large of
steps to take as you work your powder charge up to the rated velocity
that loading manuals indicate. Remember that this graph is only
valid for the combination of reloading components used for the
construction of this graph. Any changes, be it bullet, primer,
or powder requires a new and different graph be created. I graph
variations such as normal bullet seating depth, bullet pre-load,
and MOLY coating of the bullet on the same graph for comparison,
but label all the data points in a way that I can not get them
mixed up. I want to be able to sort out all the data points in
case I find something unusual in the future and have to reconstruct
old testing. That is a lot more cost and time efficient then redoing
old tests, possibly for freezing temperatures in the middle of
the summer. Take care all the while to look for signs of high
pressure just in case there is something unique about your particular
gun.
Some additional information that can be obtained from this
graph is the range of velocities that will be observed at any
one powder charge . this is an indication of how consistently
the powder is burning. In short range shooting some variation
is no big thing, but at the longer ranged the variation in velocity
will give you a vertical elongation to your groups as the bullets
drop at varying rates. One particular powder when fired in my
300 win mag at low temperatures burns just fine, but when the
temperature moves up to 80 degrees and above the powder starts
to burn in a very different way resulting in two distinct velocities
forming on this graph for the same powder charge. The graph showed
these velocities were separated by 250 ft/sec, this is the equivalent
of changing the powder charge six grains! The results were two
distinctly different groups forming on the target, at a distance
of 100 yd. these two groups were 2.5 inches apart from each other.
Without this velocity information I would have been sorting brass,
bullets and anything else I could measure or weigh to look for
the cause. Changing the powder solved it immediately.
The graph will also show if one powder charge is burning
more consistently (thus producing a tighter range of velocities)
than others. Even if the most consistent powder charge is not
at the maximum velocity sometimes hitting the target where you
want takes precedence over possibly missing with a real killer
bullet. Of course you would have had the satisfaction of knowing
that if it did hit it would have been spectacular.
Once you have determined the powder charge that you would
like to use, it's time to load up a group of bullets. Load them
to the maximum over all length that will either fit in the magazine,
or fit in the chamber, allowing enough clearance for safe dependable
operation, depending on if you plan to hand load each round or
feed from the magazine. What I do for the next step is to try
to tune the bullets to compensate for the vibrations of the barrel.
I have a heavy sporter barrel on my 300 win mag which is too lite
for real accuracy, and must be tuned to reduce group size. But
if you have a target barrel it may be stiff enough that this procedure
will be of little value to you. I don't have a Bosch system or
any equivalent that tunes the barrel vibrations to match the bullet
so I must try to tune the bullet to compensate for the barrel
vibrations.
It's hard to take exact overall cartridge length measurements
from the tip of bullets, as the bullet manufacturing process does
not always put consistent tips on them. To solve this problem
I use a bullet comparator, which is just a collar that fits on
one of the jaws of a caliper to allow the over all length measurement
to be taken off of the ojive of the bullet near their maximum
bullet diameter rather then the bullet tip, As the bullet shape
will be very consistent at this point. With several bullets loaded
to maximum desired length and powder charge hand weighed (how
many is up to you, I think groups of four are minimum for any
type of testing and how many groups is dependent on how much you
want to play with this technique). I start with a group of four
identical rounds loaded to their maximum safe length depending
on how you plan to feed them. You will need a loading press with
a bullet seating die and your calipers at the range to do this.
Run a tight dry patch through the barrel to remove any oil that
may be present from the last cleaning, or your first bullet will
have to push all that oil in front of it to get out. This will
probably create a flyer and the first group will be meaningless.
Now shoot them at some reasonable distance off of a bench, to
remove your shake from the testing process. I do everything dealing
with rifles at 100 yd to allow easy comparison of all results.
Look at the group size, the smaller the better, but you don't
want any flyers under any circumstances. A tight group with a
flyer is not a tight group. Don't forget to record the velocities
of each of these shots on your graph, the more information that
you have on this graph the easier it is for you to spot potential
problems and trends. Try seating the next four bullets 10 thousandths
deeper into the case and shoot them. Each time you shoot a group
use a new target and save the old one. Mark the over all bullet
length and possibly load information on each target if your doing
several things at once. Continue doing this until you have found
a group you are happy with and then go a couple of groups further.
Take this information and record group size vs. Seating depth
size. At this time mark the center of each group right on the
target. On a separate piece of paper draw a circle representing
the bulls eye of the target, life size, and mark on this paper
the exact position of the average(center) of each of the groups. Label
the bullet over all length that applies to each point right on
this target. When finished connect the points with a line in order
of over all cartridge length. What you now have is a vibration
pattern of the end of gun barrel. If you had done this same operation
in 5 thousandths inch increments you would have a more detailed
pattern of the barrel vibration. What you are looking for in a
good load is an over all cartridge length where the group size
is small over two or three seating depths and the barrel vibration
graph shows little change in the point of impact with adjacent
seating depths. This "range" of good groups and "range"
of impact point consistency will allow for variations in temperature
and powder weight and still give acceptable performance.
If you want to take it one step further try this. The barrel
has a basic way that it wants to naturally vibrate when fired.
All bullets have some tilt in how they sit in their case, and
when a bullet is forced into the barrel canted at an angle it
only partially straightens out. This resultant canted bullet now
has its center of mass offset with the centerline of the bore.
As this bullet spins down the bore at rotation rates approaching
200 thousand rpm it adds its own shake to the barrel, this vibration
can be used to partially cancel out the basic barrel vibration.
By orienting the bullet so the point is up and firing a group,
next to the left and firing a group, and continuing with down
and to the right, you will probably find one orientation that
will give a better group then the other. Now in my experience
if you have to tune that far to get an acceptable group you are
in trouble, because any variation in how you load the ammunition
and the varying ambient temperature will have more of an effect
and your fantastic load will probably not be so fantastic the
next time at the range. A heavy stiff target barrel will cure
so many of these problems.
I have only recently started loading with MOLY coated bullets.
So I will share some of the information that I have read and tried
first hand.
There are not a great volume of people using this process
at this time so a few magazine articles and personal experience
is all I really have to go by at this time.
The lubricant itself is Molybdenum-disulfide, which is a
very good dry powder lubricant intended for use on sliding surfaces.
When this MOLY coating is impact plated on the bullet and a protective
layer of Carnauba wax is placed over it, this process is called
NECO COAT . This is a patented process developed by NECO/Nostalgia
Enterprises Company.
An overview of some of the basic characteristics of changing
from a standard uncoated bullet to a MOLY coated bullet are:
1. A loss in velocity This loss in velocity does not always
exist but in the majority of cases it is an obvious reduction.
2. a reduction in bore to bullet friction.
3. a reduction in bullet deformation due to bore contact.
4. a reduction in pressure due to the bullet being able to
accelerate faster down the bore.
5. reduction in bore wear.
6. reduction in bore fouling.
The above in more detail:
As far as the loss in velocity, I have worked up loads for
two handguns, a Glock .40 S&W with Red Dot powder and 180
gn bullets that lost 100 ft/sec and a Thompson Contender .44 mag
with H2400 powder and 200 gn bullets, that show no reduction in
velocity. In a 300 win mag rifle with 180 gn bullet and IMR-4350
I see a reduction in velocity of about 100 ft/sec. I have talked
to one other who has a rifle that shows no reduction in velocity
(I don't have any details on this at this time) so this reduction
in velocity is not a guaranteed event. In each case the lost velocity
was recovered by increasing the powder charge.
The reduction in bore to bullet friction is a two edged
sword: It allows the bullet to accelerate down the bore sooner
and faster, but the byproduct of doing this is the powder no longer
has the same high pressure and high temperature to burn in. Under
this condition the powder burns more slowly and possibly less
uniformly. To overcome this problem more powder is introduced
into the load. Due to the reduced friction the powder charge can
normally be increased to allow the bullet velocity to be increased
beyond that of an uncoated bullet. I have worked a Thompson Contender
.44 mag up to a velocity over 100 ft per sec beyond the maximum
uncoated velocity and have see no sign of excess pressure.
The reduction in bullet deformation due to barrel friction:
From what I have read, due to the lubrication of the bullet,
the barrel lands do not grind as deep groves in the bullet sides
thus reducing the drag and increasing the ballistic coefficient
of the bullet. At longer ranges this is supposed to flatten the
trajectory a noticeable amount. One person that I have talked
to said that at 1,000 yd the impact was 10 inches higher than
with the uncoated bullet.
A reduction in bore wear is a natural benefit in the use
of a good lubricant. Tests are being conducted to determine just
how much barrel life expectancy can be improved.
Reduction in bore fouling is the result of the microscopic
fissures, present in all barrels being filled by the MOLY, and
as a result minimizing the amount of powder residue that can be
forced down into these fissures. The Molly will also reduce the
amount of flame that will work itself deep into the fissures.