Being basically a revolver shooter I have never thought too much about problems
that may arise in reloading for the auto-loading handguns. I spent quite a few
years learning the tricks of reloading in order to get the most accuracy from a
revolver. It wasn't until I began playing with a 9mm Colt Combat Commander
though, that I gave any serious thought about reloading for the auto-loading
pistol. As I was to find out, reloading a 9mm so that it will fire and function
is one thing, but getting the most accuracy out of it can be another altogether.
My first step was to read through the reloading manuals. I have
some that go back as far as 1939, but basically all they give is the reloading
process and a listing of loads with different bullets and powders. There was not
much information on "why" some of the autoloaders just do not shoot as
accurately as they should. It was not until I read the new SPEER RELOADING
MANUAL #12 that I ran across any real information on "why". While the Speer
Manual has the standard reloading information, it also has a special section
dealing specifically with the 9mm and it's special needs. Beginning on page 432,
this handy section contains information that can only be found otherwise through
trial and error. While most of the information is stuff we hand-loaders SHOULD
be aware of, I found it helpful and a good point from which to work. Reading
through all the manuals by the way, was interesting and did give me some
insights. For instance, in Speer Reloading Manual #11 I found that with 9mm
handloads of 28,000 CUP (Copper Units of Pressure), should you seat the bullet
only .030" deeper into the cartridge case, the pressures jump to 62,000 CUP!!
Enough to wreck a good gun. I got the idea from this that the 9mm can be touchy
to reload and that careful attention to detail (such as over-all loaded length)
is very important.
Another thing that I found was while the 9mm cases are supposed
to be a certain length, there can be large variations, even when the cases are
from the same manufacturer. Cases should be sorted according to head-stamp
before reloading. I also found that among the guns firing the 9mm cartridge
there can be variations in bore diameters. It is helpful when you are searching
for accuracy to have bullets that fit the bore. The bore diameters can surprise
you. While the 9mm bore is supposed to be .355" I found many guns have barrel
diameters of .356" or larger. Some are as large as .358", especially among
After cleaning my empty cases I sorted them all according the
head-stamps. Before sizing, neck expanding, and priming the cases I decided to
check them for over-all length (OAL). To my surprise I found that the cases
varied by as much as .020" in length. Using six different brands and checking
ten of each, I found cartridge cases ran from .7355" in length to .755" for the
long ones. This large variation can means that some cases are not head-spacing
on the case mouth as supposed, but rather are head-spacing on the extractor.
This could account for sloppy accuracy in itself.
While checking the case lengths I decided to weigh the water
capacity of some of them and found the cases I checked to vary as much as 3.1
gr. weight of water. While gunpowder is much lighter and would not vary that
much, it still shows the internal variations from cartridge to cartridge.
After reading and checking dimensions I began to theorize that I
might be able to increase the accuracy of the 9mm - at least in my pistol - by
carefully measuring the cartridge cases and with precise loading. To test the
the theory I choose two bullets to use, the Speer 115 gr. and the Speer 147 gr.
Gold Dot hollow-points. I decided to use only CCI #500 primers and Speer cases
for reloading. For powders I choose two old-timers, Hercules Bullseye and
Unique. To keep variables at a minimum I chose arbitrarily an over-all loaded
length of 1.130". I loaded 10 at this length and function-fired them. They
worked through the action smoothly and gave no problems. What I was seeking was
a length that functioned without any hang-ups. While experimenting with OAL of
the loaded cartridge CAN increase accuracy sometimes, at this point my only goal
was to see if my idea about case lengths was valid.
The powder charge selected was in the recommended range in the
reloading manuals. I did not chronograph any of them. All I wanted was a load
that would be safe and would function in the firearm. I was not out to see how
fast they would go, but rather, could I make any difference in the accuracy by
checking the length of the cartridge cases. Reloading was done with once-fired
cases. I loaded enough to fire 6 five-shot groups with each group of
cartridges. For a greater statistical average a minimum of 10 5-shot groups
should have been used, but at the time I was short on bullets and figured 30
shots would give a good indication.
All firing was done from 25 yards using an Outers
Pistol Perch. For the first segment of testing I had four groups of cartridges.
Loaded with the 115 gr. Gold bullet and 4.7 gr. of Bullseye, the cases were
sorted as follows:
Using Unique powder I found gave slightly smaller group
averages. For some reason the pistol I was using preferred the slightly slower
powder. I feel sure that by experimenting with over-all loaded length and by
trying other powders or primers, some loads will shoot more accurately than the
ones I recorded. However, each firearm is an individual and testing needs to be
done with each one if you wish to get it to shoot to it's maximum potential.
Note though, that simply by careful attention to details I was able to increase
the useable accuracy of this particular firearm.
After studying the results of my shooting tests I decided to see
if it would hold true with cast bullets. Using what I had learned from the
previous tests, I used only 2 different lots of cases. One lot was cases picked
at random and not measured for length. The other lot was cases of .750" length.
The bullet diameters were .356", more closely fitting the bore diameter of the
Colt Combat Commander. I used four different bullets during this phase of
firing. One was a nice semi-wadcutter from BRP High Performance Cast bullets
which weighed in at 115 gr. I also had 2 bullets from MT. Baldy Cast Bullets,
both of 122 gr. weight. One was a flat point (FP) while the other was a
round-nose (RN) design. The last cast bullet was one I cast myself. In a pointed
shape, it was Lyman's version of one of the old original Luger bullets. Weighing
in at 121 gr., the Lyman number for this design is #356402. Again, testing
confirmed that in this gun at least, cases of .750" length shot the most
accurately. As I have stated before, you will have to find what case length
shoots the best in your particular firearm. However, this is a good starting
To summarize, when reloading:
1. Sort your cases by head-stamp
2. Check the over-all length of each case and sort them by length
3. Watch the over-all loaded length of the cartridges
4. Monitor your powder charges carefully
5. Determine which case length shoots the most accurately in your firearm
NOTE: ALL OTHER
GUIDELINES FOR SAFE RELOADING APPLY ALSO