For pistols, there are over 30 different calibers used in specialty handguns worldwide. However, the most common calibers sold for handguns in North America are 0.22 shorts, 0.22 longs, 0.38, 0.44 or 0.45 caliber cartridges.
Rifle calibers are much more numerous than handguns, primarily because the military have developed a host of specialty calibers for semi and full-automatic assault rifle applications. For personal use, however, the most common rifle calibers sold in the United States are 0.22 shorts, 0.22 longs, 0.223, 0.243, 0.25-06, 0.308, 0.30-06 or 0.45-70 cartridges.
Shotguns are big-bore long guns primarily used for bird hunting, although law enforcement agencies also use these weapons for additional close-in firepower. Because of the barrel diameter, shotgun cartridges are measured on the basis of "gauge" or "bore" rather caliber. However, the measuring principal is the same. Typical shotgun cartridges sold in the United States are 12 , 20, 0.410, 16, and 10 gauge.