The Gun Digest Book of .22 Rimfire. James E. House

size. A granulation known as FFFFg (very fine, often referred to as “4F”) is a very fast-burning form while a coarse granulation designated as Fg is comparatively slow burning. Black powder used most often in rifles is FFg (medium) while FFFg (fine) is used in handguns or rifles of small caliber.

      The 41 Swiss (left) and 22 Short (right) illustrate the range of cartridges that were eventually produced in rimfire calibers.

      One of the early designs for a self-contained cartridge is known as the pinfire, and it dates from about 1830 when Monsieur Casimir Le Facheux invented it in Paris. The cartridge contained a bullet, propellant (black powder), and a primer. However, the blow of the hammer was transmitted to the primer by means of a pin that stuck out of the side of the case at the rear. This meant that the cartridge had to be oriented in the chamber in such a way that the hammer would strike the pin to push it into the case to crush the primer. Although placing the cartridges in the firearm in the correct orientation made loading slow by today’s standards, it was still rapid compared to loading a muzzle-loader. With pinfire cartridges, there was also the possibility that the protruding pin could be struck accidentally which could force it into the case causing the cartridge to fire. From the standpoint of safety, the pinfire left a lot to be desired. However, cartridges of this type were fairly popular in Europe and some shotguns employed this type of cartridge.

      Another cartridge design consisted of a closed tube that contained the bullet and propellant with the primer being contained in a small protruding portion at the rear end of the tube. This type of cartridge, known as the Moore teat fire, was loaded into the front of the cylinder of a revolver with the teat at the rear where it could be struck by the hammer. The front end of the cartridge was flared to form a retaining flange that fit against the front of the cylinder. Cartridges of this design were produced in the mid-1800s. Because the protrusion that held the primer was located in the center of the cartridge head, it was actually a center fire design rather than a true rim fire.

      Each of the early cartridge designs described above contained a primer that was sensitive to shock. Subsequent designs would also rely on shock or percussion to cause the primer to explode, but the primer would be located differently in the cartridge. In 1845, a man named Louis N. Flobert in France loaded a round ball in a percussion cap and produced a small cartridge known as the 22 caliber BB (bulleted breech) cap. Power was the result of the primer since no powder was used. Some American versions of this cartridge employed a conical bullet (hence these were known as CB caps) that was loaded over a small powder charge. In 1851 at an exhibition in London, Horace Smith and Daniel B. Wesson became convinced that this cartridge design could be refined.

      The rimfire cartridge was developed by producing a cartridge case with a flange or rim of larger diameter than the body by folding the rear of the case over on itself. The rim was hollow and allowed the priming mixture to be contained within it. The priming mixture was placed in the case while wet and spinning the case caused the mixture to fill the hollow rim. When the primer was dried, it then became sensitive to shock. Crushing the rim by a forward blow of the firing pin caused the primer contained within it to explode which in turn ignited the powder charge.

      A short, self-contained 22 caliber cartridge called the Number One Cartridge (essentially identical to the 22 Short of today except for primer and propellant) was introduced in 1854 by Smith & Wesson for use in a small revolver. The revolver was designated as the Smith & Wesson Model 1 First Issue produced from 1857 to 1860. It was followed by the Model 1 Second Issue that was produced from 1860 to 1868 and the Third Issue from 1868-1881. All issues of the Model 1 had a hinge that connected the barrel to the top of the frame at the front end. It was opened by means of a latch at the bottom of the front edge of the frame that allowed the barrel to be tipped up so that the cylinder could be removed for loading and unloading. The cartridge employed a 29-grain bullet that was propelled by 3 to 4 grains of black powder contained in a case that was slightly longer than that of the BB cap. A patent was granted on August 8, 1854 for the rimfire cartridge that was the precursor of the 22 Short. While certainly no powerhouse, the 22 Short has been used as a target load for many years in firearms designed specifically for that cartridge. As strange as it may seem, the 22 Short was originally viewed as a self-defense load! In modern times, small semiautomatic pistols chambered for the 22 Short have been produced for concealed carry and self-defense. The 29-grain bullet from the 22 Short high-velocity load has a velocity of approximately 1,095 ft/sec while the 27-grain hollow-point bullet has a velocity that is a slightly higher.

      Introduced in 1887, the 22 Long Rifle (LR) is by far the most popular rimfire cartridge. However, another 22 rimfire cartridge appeared in the 30-year interval between the introduction of the Short and the Long Rifle cartridges. That cartridge, the 22 Long, was introduced in 1871 and made use of a 29-grain bullet propelled by a charge of 5 grains of black powder. Like other 22 rimfires, it eventually became loaded with smokeless powder. The current 22 Long high-velocity cartridge produced by CCI has an advertised muzzle velocity of 1,215 ft/sec, which is about 100 ft/sec higher than the 22 Short. Any difference in power is more imagined than real, and there is no logical reason for the 22 Long to survive. Most of the ammunition companies have ceased production of the 22 Long.

      When we come to the 22 LR we arrive at a cartridge that is the most popular and widely used metallic cartridge that exists. It is used throughout the world for recreation, competition, and hunting. The original load consisted of a 40-grain bullet and a 5-grain charge of black powder. Ammunition in 22 LR caliber is loaded in many parts of the world and in some instances to the highest level of technical perfection. The accuracy capability built into a competition rifle chambered for the 22 LR is matched by several types of ammunition that are specifically designed for competition at the highest level. Such ammunition is a far cry from the old black powder loads with corrosive priming that appeared in the 1880s. In later chapters, some of the characteristics of the modern “high-velocity” 22 LR loads will be described. The 22 LR uses a bullet of 0.223 inch diameter that has a short section that is smaller in diameter (the heel) that fits inside the case. The lubricated portion of the bullet is outside the case.

      While the target shooter has special ammunition available, the hunter of small game and pests has not been left out. The 22 LR high-speed solid uses a 40-grain bullet that has a muzzle velocity of approximately 1,235 ft/sec while the 36- to 38-grain hollow-points are about 40 to 50 ft/sec faster. Other specialty loads will be described elsewhere in this chapter and in several later chapters. The 22 LR is in many ways the most useful cartridge in existence. A rifle or handgun chambered for this round can be used for many purposes.

22 Winchester Rim Fire (WRF)

      In 1890, Winchester introduced a pump-action rifle that is quite possibly the most famous 22 pump rifle ever produced. Designated as the Model 1890 (also known as the Model 90 and some rifles are so marked), the rifle chambered either the 22 Short or a new rimfire cartridge known as the 22 Winchester Rim Fire (WRF) or Winchester Special. The 45-grain flat-point bullet was offered in several loads, some of which gave a velocity as high as 1,400 ft/sec. The original load consisted of 7.5 grains of black powder and it had a muzzle velocity of 1,100 to 1,200 ft/sec. Remington used essentially the same case loaded with a round-nose bullet as the 22 Remington Special. The 22 WRF was popular for many years, but because it offered little advantage over the 22 LR, its popularity declined as the 22 LR became more highly developed.

      The 22 WRF (right) is a shorter cartridge than the 22 WMR (left) but has almost identical case dimensions except for length.

      The 22 WRF case is larger in diameter than that of the 22 LR. As a result, a bullet of 0.224” diameter fits inside the case mouth without having a section of smaller diameter at the base. This is also the situation with the 22 Winchester Magnum Rimfire (WMR) which has almost identical dimensions as the 22 WRF except for length. Therefore, the 22 WRF cartridges can be fired in rifles chambered for the 22 WMR, and they provide a lower-powered (if not lower priced) alternative to the magnum round. In my bolt-action Ruger 77/22M, the CCI 22 WRF ammunition delivers excellent accuracy as will be described in Chapter 15.