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

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Rimfire handguns are produced in the (left to right) calibers 17 Mach 2, 22 LR, 17 HMR, and 22 WMR.

The fraction by which the velocity from a handgun is lower than that given by a rifle depends on several factors. First, even with the same barrel length (which does not include the length of the cylinder), a revolver will generally give a velocity that is approximately 50 ft/sec lower than that of a semiautomatic. As will be discussed in Chapter 7, most types of ammunition give about the same velocity from a 6-inch barreled revolver as from a semiautomatic having a 4.5-inch barrel. Of course, the length of the gap between the cylinder and barrel has a significant effect. A gap of 0.003 inches results in less velocity loss than does a gap of 0.007 inches.

A semiautomatic with a 5.5-inch barrel will give approximately 50 ft/sec higher than one with a 4.5-inch barrel (see the table of velocities presented in Chapter 7). It should be remembered that there are other factors that influence bullet velocity from semiautomatic handguns. Dimensions of the chamber and bore as well as bore smoothness have some effect on velocity. Therefore, it is possible for a particular handgun with a 4-inch barrel to give velocities that are as high or higher than those from another specimen with a 4.5 or 5-inch barrel.