2.11 Caliber

Rifles and handguns are measured in caliber. Caliber is a measurement of the diameter of the bullet or the bore. Caliber is generally measured in hundredths or thousandths of an inch. Two calibers using inches as a measurement are:

• .22—Means 22/100th of an inch. A cartridge example is the .22 LR.
• .30—Means 30/100th of an inch. A cartridge example is the .30-30.

A decimal point (.) always precedes the caliber when using inches.

Sometimes the metric system (millimeters) is used. Two metric calibers are:

• 6 mm—Has a bore diameter of 6 mm. Examples are 6 x 47 and 6 mm Remington.
• 7 mm—Has a bore diameter of 7 mm. Examples are 7 x 57 and 7 mm-08.

The larger the caliber number, the larger the diameter of bullet that the gun shoots. For example, a 7 x 57 rifle uses a larger diameter bullet than a 6mm Remington rifle. A .30-30 rifle shoots a larger diameter bullet than a .223 Remington rifle.

In tubular magazines, the bullet tip of one cartridge rests directly on the primer of the cartridge immediately ahead. For this reason, use only rounded or blunt tips in tubular magazines.