Читать книгу The Gun Digest Book of .22 Rimfire. Rifles·Pistols·Ammunition онлайн

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As firearm technology developed, so did the chemistry of explosives. It was discovered that mercury fulminate exploded violently when it was struck. Therefore, percussion caps were produced which consisted of a small amount of mercury fulminate contained in a small copper cup that fitted over a hollow nipple. When the hammer fell and struck the cap, the mercury fulminate in the percussion cap exploded which ignited the powder charge as fire was directed from the primer into the barrel breech. The percussion cap was introduced in the early 1800s, and its use in muzzle loading rifles continues to the present time.

Caplock rifles of yesterday and today are relatively reliable devices. This author has fired many rounds through his muzzle loading rifles with only a few instances of misfiring or delayed firing (known as a hang fire). Loading a caplock rifle is a slow process because the powder charge must be measured and poured into the barrel and a projectile loaded on top of the charge. The process is slightly faster if the projectile is a “bullet” rather than a lead ball that is used with a lubricated cloth patch. New developments in muzzle loading make use of propellant that is compressed into pellets of known weight. One or more of these pellets can be dropped down the barrel and projectile loaded on this charge. It became apparent that producing a single unit containing the primer, propellant, and projectile that could be loaded in one operation would be a great convenience. That is exactly the impetus that led to the development of so-called metallic cartridges. However, there still remained the problem of where to place the primer in the cartridge and how to cause it to explode reliably to ignite the powder charge. Attempts to solve that problem led to several early designs in metallic cartridge ammunition.