58
•
Cartridge types head space differently. Rimless auto pistol cases headspace on the mouth of the case. Rimmed
cases headspace on the rim.
•
When a straight wall cartridge is fired, the case expands in diameter to take up all the available space in the
chamber and seals in the propellant gases. After being fired the cartridge case “springs back” so the case can be
extracted from the chamber. The case does not return to its original unfired dimensions. Therefore, the case must
be sized. Sizing of the straight-walled rimmed or rimless case “squeezes” the case back to its original diameter so
that it will fit in any firearm and hold a bullet. A bullet will fall through the mouth/neck of an un-sized case.
14.4.
Documentation
•
It is important to keep records of the important parameters that were used in reloading the cartridge in a record
book and labeling the cartridge storage container. A quantity of 100” stick-on” labels with loading parameters is
available from Dillion PN10446—see below. Recording additional data such as the Date and the Powder Lot
number is also recommended.
15.
PRIMER BASICS
•
DANGER! Primers contain a small amount of a shock-sensitive chemical that explodes when struck by a firing pin
or hammer which then sets off the powder/propellant and provides an initial pressure to assist the propellant to
reach a self-sustaining burn. It is also part of the propellant gas sealing system. Primer elements are shown below.
Primers must be installed/seated to a recommended .002” to .006” (.008” Max.) below flush so that the Anvil
contacts the bottom of the primer pocket to provide reliable ignition.
Reloading Stick-On
Label PN10446
Summary of Contents for Square Deal B
Page 50: ...50 13 DILLON PRECISION Square Deal B EXPLODED VIEWS AND PARTS IDENTIFIER 13 1 Main Assembly ...
Page 51: ...51 13 2 Frame and Lower Assembly Index Assembly Index Assembly installed in Frame Index Pawl ...
Page 52: ...52 13 3 Typical Toolhead Assembly 45ACP Shown ...
Page 53: ...53 13 4 Automatic Primer Assembly ...
Page 55: ...55 13 6 Primer Early Warning System ...