The History of Centerfire Ammunition Advertisement
Centerfire cartridges are by far the most prevalent form of
ammunition today, but the term "cartridge" originally referred to a paper
tube filled with powder and, later, both powder and a bullet. These were
used in muzzle loading firearms. Carrying a pre-measured portion of powder
saved the shooter time in that they did not have to measure out powder from
a flask every time they loaded their firearm. In the 19th century, many different designs for metallic cartridges
emerged. These included needlefire cartridges, in which a needle pierced the
cartridge and ignited a percussion cap at the base of the bullet, pinfire
cartridges in which a pin perpendicular to the case ignited the primer, and
rimfire cartridges, in which the primer is in the rim and ignited when the
firing pin crushes a small section of the rim. The rimfire design is still in wide use in .22 caliber cartridges.
A drawback of rimfire cartridges is that they must be made of relatively
thin metal to allow the rim to be crushed, and thus can not handle high
pressures. The centerfire design emerged first in shotguns, and the shotgun
shells introduced in the 1850s with primers in the center of brass and paper
uppers are largely the same in design as shot shells today -- the only
difference is that contemporary shells now generally use plastic rather than
paper for the uppers. The modern centerfire cartridge was developed in slightly different
forms at almost exactly the same time by Englishman Edward Boxer and the
American Hiram Berdan, both army officers, who independently developed
designs for primers that fit into the base of a metallic cartridge. Both had
finalized their designs by the mid-1860s. The Berdan and Boxer primers
differ in design in that the Berdan primer uses a dome that is crushed by
the firing pin, whereas the Boxer primer uses a small cap that is driven
against a plate by the firing pin. The Boxer primer is pressed into the cartridge, making it
relatively easy to remove and replace for reloading. The Berdan primer, by
contrast, is formed into the case head, and it is much more difficult to
reload a Berdan-primed cartridge. In modern ammunition, Boxer-primed
cartridges are more common in commercial ammunition from manufacturers in
the United States. Berdan-primed cartridges are generally encountered in
military-surplus ammunition from European and Asian countries. The introduction of smokeless powder and the ability to manufacture
ammunition to exacting tolerances allowed many developments in firearms
design, but the basic architecture of the centerfire metallic cartridge
remains the same today as when it was perfected by Berdan and Boxer. From GunsAmmo
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