Understanding the caliber of a rifle or handgun is important because it tells you the size and type of bullet you need for your gun. Caliber determines how much damage one can inflict on a target and if that damage is appropriate for the expected target. For example, you wouldn’t want to put a huge hole in a deer while hunting.
How is Caliber Measured?
Caliber is expressed in metric or imperial measurements, depending on where the gun was developed. If it is from the United States, then it is likely to be in imperial measurements. However, if it is from somewhere else in the world, it is probably metric.
Handguns that say .22 caliber or .45 caliber are imperial measurements, and the .22 or the .45 is the nominal bore diameter of a firearm measured in inches. Usually, when this is said aloud, the decimal point is dropped, and the firearm is called a twenty-two caliber, or twenty-two.
The easiest way to determine the caliber of a firearm is to check the barrel or the chamber of the gun. The caliber is usually imprinted on it. If the gun is old or you can’t read the imprint on it, then you can always measure the caliber manually.
There are two ways to measure the caliber of your firearm. First, you can measure the distance between the high points of the rifling, or you can measure the opposing low points in the grooves of the rifling. Cartridges designed outside the United States tend to use the high-point measurement, while measurements in the United States use the low points.
Understanding caliber allows you to know what bullets your gun needs and how much damage your gun can inflict on a target. For most guns, the caliber is imprinted on the barrel or chamber of the gun. However, if the gun is old or you can’t decipher the imprint, the caliber can be measured manually.