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

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It is easy to forget that rimfire cartridges were produced in shorter lengths for use in revolvers and longer versions for rifles in many calibers.

Note how the current 22 Short and Long Rifle have parallels in the 25 Short and Long cartridges of a century ago.

Propellants and Primers

As the quest for better ammunition continued, it was recognized that black powder left a residue that attracted moisture and led to corrosion. Barrel life of the firearm was nowhere near as long as it is today. In the late 1890s, a new type of propellant was developed by making use of an entirely different type of chemistry. When cotton is nitrated with a mixture of nitric and sulfuric acids, the product is known as nitrocellulose, and it burns very rapidly when ignited. Moreover, the combustion produces very little smoke so this propellant is known as “smokeless” powder. This book is not the place for a review of propellant technology, but it should be mentioned that the burning rate of nitrocellulose can be controlled to a great extent by the particle size. Therefore, it is possible to produce nitrocellulose and tailor it for use in cartridges having different sizes. Another development in propellant technology resulted in a type of powder known as double-base powder. This type of propellant makes use of nitrocellulose to which has been added a small percentage of nitroglycerin. In addition to varying the particle size of the propellant, various additives are included to impart particular properties such as flowing ease, reduction of static electricity, flash reduction, etc. By controlling these characteristics, a large number of types of propellants have been developed with burning rates that vary enormously. Some propellants work best in small cases such as the 22 Short or 25 ACP while others perform best in large cases such as the 300 Winchester Magnum.