Understanding the Definition of a Centerfire Gun or Ammunition

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A firearm or ammunition cartridge that is fired by a strike from a firing pin in the center of flat cartridge head is called a centerfire. Another type of the rimfire, which, as the name implies, is fired with a strike from the firing pin on the rim of the flat cartridge head. 

While modern shotguns and shotgun shells also fire from a strike from a centerfire pin, but the term is not normally used to describe shotguns and their shells, but only the ammunition for rifles, pistols, and revolvers. This term may also refer to a  gun which fires centerfire cartridge ammunition, i.e. "centerfire rifle," etc. Except for a few .17 and .22 guns, most cartridge firearms now use centerfire ammunition.


Genuine centerfire ammunition similar to the modern design was invented by the Frenchman Clement Pottet in 1829, though the design was not perfected until 1855. Improvements were made to the cartridge design by several designers,  Benjamin Houllier, Gastinne Renette, Charles Lancaster, George Morse, Francois Schneider, Hiram Berdan and Edward Mounier Boxer. Centerfire ammunition saw wide use in the US as early as the 1860s, and although alternative forms of ammunition have surfaced from time to time since then, none have had the staying power of the centerfire metallic cartridge, which is by far the most widely-used type of ammunition in the world.

Cartridge Design and Advantages

A typical centerfire cartridge will contain a primer pocket formed in the center of its head or base. A separate primer is inserted into that pocket during manufacture. A powder charge is then placed inside the cartridge case, followed by the bullet, which completes the process of loading a round of ammunition. Because the base of a centerfire round is stronger than that of a rimfire, the cartridge can hold a larger charge, thereby creating higher bullet velocity, a decided advantage with larger-caliber ammunition. 

Centerfire ammunition is easier to manufacture than rimfire ammunition and is also more reliable. It also enjoys the benefit of usually being fairly easy to reload, a decided advantage for avid sportsmen, since brass cartridge jackets are a significant cost. This ease of reloading is a feature of most centerfire ammunition that has one centrally located flash hole in the middle of the primer pocket. But some cartridges are Berdan-primed--which means they have a pair of flash holes instead of just the one.

A single flash hole makes for easy reloading because the spent primer can be easily removed by use of a de-priming pin placed through the flash hole from the inside of the cartridge case. But the twin holes of Berdan-primed cases render primer removal difficult, and most reloaders consider it impractical to reload for that reason.