Modern
Firearms
What You
Should Know | Evolution
| Types of Firearms | Basic
Firearm Actions | Final QuizCaliber and Gauge
The bore is the inside of the barrel where the bullet or shot travels. The distance across the bore is called bore diameter. In a shotgun, it is measured in gauge. In a rifle or handgun, it is measured in caliber (calibre for Canada). Caliber is the distance across the lands.
