.22 CB
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.22 CB Cap (Conical Ball Cap) is a variety of .22 caliber rimfire ammunition which has a very small propellant charge (usually no gunpowder, just the primer), resulting in a low muzzle velocity of between 350 and 700 ft/s (110 to 210 m/s). This is similar to the muzzle velocity produced by a low to mid-power .22 pellet gun, however it should be noted that the bullet from a .22 CB cartridge is significantly heavier than a typical airgun pellet and therefore carries more energy. Due to their low power, CB rounds can be trapped by most pellet gun traps. In longer rifle barrels the CB has a seemingly non-exsistent, very quiet report due to the lack of residual pressure at the muzzle (see Internal ballistics). But when fired in a pistol, surprisingly, the noise exceeds that of the larger Long Rifle round fired from a rifle, and velocity suffers even more (>500 FPS). CBs are, generally speaking, made for rifles. CB rounds are often used for indoor shooting practice or for small pest control in areas where a limited range is an advantage due to crowding. Care should be taken when firing CB rounds indoors, since the priming compound used in most cartridges contains lead compounds. Lack of adequate ventilation can lead to inhalation of the lead compounds in the soot, which in the long term can lead to lead poisoning. Since CB rounds have little or no gunpowder to generate the high pressures and large volumes of gas found in normal ammunition, the soot from the primer is more heavily deposited in the barrel and chamber and on the fired case. Firearms should be cleaned, and the user's hands washed carefully to remove this residue.
The original .22 CB cartridge has the same case as the .22 BB, but there are now low-power .22 rounds sold as .22 CB Short and .22 CB Long which come in the more common .22 rimfire cartridge cases. The longer cases will allow the rounds to be fired in magazine fed firearms, in which the tiny CB Cap cases would jam. So while having the same length, the modern 22 CB Short and the 22 Short are two different cartridges. The CB has a reduced powder load and is kept (as mentioned above) between 350 and 700 FPS, while the Short with an increased powder amount launches the same 29gr bullet around and above 1000 FPS.
[edit] Specifications
- Case length:
- Cap: 0.284 in (7.2 mm)
- Short: 0.423 in (10.7 mm)
- Long: 0.595 in (15.1 mm)
- Bullet weight:
- typically 20 to 29 grains (1.30 to 1.88 g)
