I hope this four-part blog series clears up some of the confusion surrounding pistol ammunition: types, naming conversion, science and generally accepted information.
Part 1: basics
Components and how they work:
Cartridges are made up of four components: bullet, casting, powder, and primer. When a gun is fired its hammer or striker hits the primer. The primer detonates and starts a secondary detonation of the powder. The detonation of the powder propels the bullet forward. The final component, the casting, holds all the components together.
Size:
The different cartridges types are named after the diameter (caliber) of there bullets. American and English cartridges are measured in inches while European cartridges are measured using millimeters.
Listed from smallest to largest are some of the more popular pistol cartridge types: .22 cal, .380 ACP, 9mm, .40 cal, and .45 ACP. Each cartridge type has a history and many alternate names. For example the 9mm can be referred to as: 9x19mm, 9mm Nato, and 9mm Luger. In the name 9x19mm the “9” is the measure of the diameter of the bullet in millimeters, while the 19mm refers to the height of the casting. 9mm NATO cartridge is the official cartridge adapted by NATO and is considered an overpressure variant of the 9x19mm. The 9mm Luger is named after Georg Luger, the original designer of the 9x19mm. There are some exceptions to the naming rule; the .380 ACP is good example of this. The .380 ACP (Automatic Colt Pistol) was designed by John Browning and introduced by Colt in 1908. Even though you’d expect the .380 ACP’s diameter to be .380th of an inch it is actually .355 of an inch (9mm). The number “.380” was most likely selected for marketing reasons. The dimensions of the .380 ACP are: 9mm bullet diameter and 17mm casting height. Alternate names for the .380 ACP are: .380 Auto, 9mm Browning, 9mm Corto, 9mm Court, 9mm Kratak, 9mm Kurz, 9mm Scurt, 9mm Short, and 9x17mm.
Please stay tuned for part 2 the science behind “Stopping Power”.
Table of Contents:
Part 1: Components and Naming (12/11/09)
Part 2: Stopping Power, Energy Transfer, Hydrostatic Shock (12/11/09)
Part 3: Weight and Fill (12/15/09)
Part 4: Generally Accepted Information (12/15/09)
