In the early days of fixed ammunition, 1840 to 1870 or so, the best way of doing things was far from being settled or self-evident. Many designers worldwide had the same idea: concentrate the primer, powder, and projectile in a single self-contained cartridge. A cartridge could be made of many materials, but whatever it was made of, it offered speedier loading, a simpler manual of arms than any externally-primed system, more ignition reliability, more consistency from shot-to-shot, and even a small degree of waterproofing. With the advantages so clearly evident, next task was to make the cartridge, and a weapon to fire it. In Europe, pin- and needle-fire arms were up first; in America, rim-fire guns were first.
Pinfire was invented by Casimir Lefaucheux in the late 1820s and 1830s, as an improvement of Prélat & Pauly’s needle-fire design of the early 1800s. Johann von Dreyse, who had worked for Pauly, developed a version of the needle gun that became the Prussian standard, the Dreyse Needle Gun, and the French countered with a needle-gun of their own, the Chassepot. Russia briefly adopted the Karl. All these pinfire or needle-fire weapons would be replaced by centerfire cartridge firearms in good time.
Meanwhile, rimfire, originally developed for the indoor guns of Flobert, was adapted to .22 caliber in the .22 short Smith & Wesson Model 1 revolver. Early rimfire cartridges all used black powder exclusively, but “rimfire” then was not always, as it is now, a synonym for “smallbore.” Larger cartridges than the .22, like the .44 rimfire used in the original Henry rifle, and the .56-56 Spencer, evolved (and weapons evolved to use them). By the end of the Civil War, quite a few Union cavalrymen were armed with breechloading rimfire repeaters.
Centerfire offered advantages over rimfire. It uses less priming mixture, and that, and the central location of the centerfire primer, makes rounds more stable in handling, and also ensures the primer can ignite the propellant more evenly.
The first centerfire cartridges were made much like rimfire cartridges, drawn from thin cups of copper into a thin-sheet construction of uniform thickness, or thinness really, like the familiar .22 rimfire. An internal cup lined the so-called “balloon head” cartridge and had a small cup in it with a place for priming compound, an impact-sensitive fulminate or styphnate of a reactive metal.
For example, the Martin and later Benet cartridges used in the early center-fire Allin conversions of muzzle-loading Springfield rifle-muskets were this type; even the casings recovered at the Little Big Horn were like this. These cartridges were, like rimfires, not practically reloadable. While today, reloading is largely practiced by hobbyists, in the middle of the 19th Century, it was considered beneficial for soldiers and frontiersmen in the remote extents of the American West and the outposts of the British Empire to be able to reload spent casings.
There are two types of priming systems for centerfire cartrifge in use today. Both date back 150 years, to 1866, and in all that time, neither has overcome the other. That is because each one offers specific advantages — the system you choose depends entirely on which advantages you give more weight to.
Each system was developed by a man who had earned the rank of Colonel in his national Army: Hiram Berdan of the United States and Edward M. Boxer of Great Britain. Both were Ordnance officers, although Berdan did distinguish himself in command of a Sharpshooters (skirmishers or light infantry) unit in the Civil War. Boxer was superintendent of the laboratory at Woolwich Arsenal. (Boxer’s family produced many distinguished Army and Navy officers).
Originally, Berdan’s system used a drawn brass case with a heavy, solid head, a primer cup with an integral anvil, and two flash holes in the primer cup set 180º apart. Boxer invented a self-contained primer with its own anvil, and originally intended it to be used in a thin-sheet copper case with a single flash hole on the centerline. The strength advantages of the Berdan case were so evident that Boxer’s system was quickly adapted to the stronger heavy-base drawn case. Berdan had patented his integral-anvil primer pocket, but not the drawn-brass heavy-head cartridge design.
Accordingly, long before the turn of the century, the only remaining difference was the primer and primer pocket design.
The principal advantage of Boxer’s primers is that they lend themselves to reloading. Berdan’s casings were intended to be disposable. Boxer cases are easily deprimed with a needle that poked through the single larger flash hole. Berdan primers are best deprimed hydraulically, by forcing an incompressible fluid into the case. Boxer primers are also a little more robust and easier to handle than Berdan primers. At an industrial level, it may be cheaper to make Berdan primed ammunition. While making a Berdan case is a little more complicated and costly than making a Boxer case, the complex multipart Boxer primer is an assembly of tiny parts that must be precision manufactured to be reliable. The primer complexity more than offsets the case simplicity.
The Boxer system took off in the United States, where cartridge reloading was very common among individuals on the frontier, and where much more ammunition is produced for the civilian market than for the armed forces, and in many more varieties. In Europe, where firearms were more likely to be produced by state arsenals for state actors, in few standardized calibers, the economies of scale justified Berdan priming.
In the US, surplus ammunition with Berdan primers is likely to be corrosively primed, but that is correlation without causation. Either kind of primer can contain a corrosive or a less-corrosive (We don’t think any of them is truly non corrosive) impact-sensitive priming compound. The older the ammo, the more certainty that its primer will leave highly corrosive salts in the bore and action of a firearm, and that’s true of Boxer and Berdan primed ammo alike.