Help a Junior Shooter - Please make a generous Donation to the Camp Perry
by Stuart A. Leach a.k.a. "the Colorado Gray Fox"
Every NRA Highpower shooter
is tempted to use the once-fired 30-06, 7.62/308 and 5.56/223 military brass
advertised in magazines and catalogs. The price is usually low compared with
virgin commercial cases, and it somehow seems right to use GI brass in a service
rifle. There are a few things to know about military brass before you start
using it for competition, and I'd like to offer a few hints and tips.
Military brass is available
from various sources, and in various conditions. Dealers actually package by
weight, so the box or bag may be a few rounds short or long. Cheapest will be
standard NATO ball cases, straight from the training ranges. It will be dirty,
some cases will be damaged, and may be from mixed lots or several makers. It may
have been fired in rifles or machine guns. As price goes up, so does quality-
cleaner, sorted by headstamp, etc. The highest grade is once fired GI match
brass, which will have been fired in rifles, and has no primer crimp. GI
7.62/308 match is getting scarce as military competitors switch to the M16.
Keep in mind that military
7.62/308 and 30-06 brass contains more metal than commercial cases. GI 30
caliber cases weigh 7 to 10% more than civilian brass; the extra metal is found
in the rear third of the case. This means less internal volume, and powder
charges need to be reduced to avoid excessive pressure. There is little
difference between military and commercial 223Rem/5.56NATO brass.
Some dealers sell brass that
has been "processed"- tumble cleaned, de-primed, and the primer retaining crimp
removed. While this saves some work, I have seen a batch of 5.56/223 where the
primer pocket was reamed too deeply, leaving the new primer unsupported for half
its depth. Better to do the work yourself.
Assuming we have a batch of
NATO ball cases, here are the steps to get it ready for use:
Inspect the cases, and throw
out any with serious damage to mouth or rim. True up out-of-round case mouths
with a tapered punch, such as a nail set, so they will enter the sizing die
De-prime with a Lee or RCBS
de-prime die. Then clean well in tumbler or vibratory cleaner for several hours.
All the dirt and grit must be removed to avoid damage to sizing dies.
If the cases were fired in a
loose chambered rifle, or a machine gun, a regular sizing die may not reduce the
base diameter enough to chamber in your rifle. The thicker web and case walls
spring back more than civilian cases. We usually don't know what sort of gun or
guns the brass came from, so it's best to return each case to minimum dimensions
before loading and firing the first time in your rifle. Lube the cases well,
inside and out, and size in a special small base die. I share small base dies
with other shooters. Clean again to remove sizing lube. Trim to length, then
chamfer and deburr case mouths.
Ream or swage out the primer
crimp. Reaming cuts away the crimp, using an inexpensive hand tool. Reaming
carelessly can result in an oversize or oval pocket. Swaging moves metal out of
the way, and slightly work hardens the pocket area. Swaging tools (RCBS is
adequate, Dillon is superb) are more costly and complex, but once adjusted do a
better job than reaming. Use a case mouth chamfer tool to put a light chamfer on
the pocket to ease entry of the new primer.
For best results, use a flash
hole reamer to remove internal burrs. A primer pocket uniformer will also help
insure consistent ignition by making the pockets of equal depth, and flat on the