Tech Line & Tips (FAQs)
Cartridge Denting
One
of the most common reloading problems that initiates a call to our
customer service technicians, is the denting of cartridge cases
shoulders and bodies during the sizing process. There are several
different causes of these dents and each has its own unique cure.
Shipping Lubricant
When shipped from the factory, all reloading dies are
protected with a moisture displacing oil for shipment and storage.
During prolonged storage, this shipping oil may migrate to one side of
the die and harden. Before using your new dies, they should be cleaned
to remove all traces of the shipping oil. Using a quality bore solvent
and a brass bristle brush, scrub the interior of the dies out and then
carefully dry them. Be sure no solvent remains in the threaded area at
the top of the die that may later run down and cause sizing
difficulties. An air compressor will greatly assist in drying the dies
after cleaning.
Excess Lubricant
A common and obvious cause of shoulder denting is the application of
excessive lubricant before the case is run into the sizing die. When
using a high-grade case lubricant, such as our "Imperial Sizing Die Wax"
or "Original Formula", a light, even coat applied to the body of the
cartridge case is all that is necessary. The lubricant can be applied
using your fingers or our lubricant pad. Be sure to wipe the excess
lubricant off the case shoulder and neck area, leaving only a thin film
remaining.
Lubricant can also build up over time in the sizing die body. Each
time the die is used, a new layer of lubricant is added. The lubricant
then hardens during storage and gradually builds up until the
accumulation starts denting the cartridge cases. Clean the die using the
above recommended procedure to restore the interior of the die.
Excess Sizing
Another common cause of cartridge case denting is excessively sizing
the case. In this case, the "dent" is actually a "kink." When the sizing
die dimensions aren't closely matched to the chamber dimensions, the
case buckles away from the die during sizing. This can be caused by an
oversize chamber, an undersize die, excessively bumping the case
shoulder or any combination of the three.
A properly adjusted full length sizing or body die should be set up
to bump the case shoulder 0.002" for most rifles. When sizing cases for
an autoloader, bump the shoulder .004" to .006". This figure can be
verified with the Redding Instant Indicator Headspace and Bullet
Comparator. Using a Redding's Competition Shellholder Set will make
achieving precise shoulder bump a snap. See the Redding catalog or
website for more information.
To check for excessive case sizing, compare the dimensions of a fired
case and one that has been resized. The diameter of the fired case at
any point should not be reduced more than 0.005". If you find that your
cases are being sized more than this, an oversize chamber or undersize
die may be the problem. Sometimes, it may be possible to polish or hone
the die to better match the chamber. Check with the factory if you
suspect this problem.
A popular misconception is that sizing dies need a "vent hole" to
release air or excessive lubricant. It can be easily demonstrated that a
vented die will also dent cases if excessive lubricant is applied to
the cases, case dimensions are not compatible with the sizing die or the
case shoulder is being bumped excessively.